The BGP, which RFC 1771 defines, allows you to create loop-free interdomain routing between autonomous systems (ASs). In order to send the information to external ASs, there must be an assurance of the reachability for networks.
When BGP runs between routers that belong to two different ASs, this is called exterior BGP (eBGP). Two BGP routers become neighbors after the routers establish a TCP connection between each other.
After the TCP connection is up, the routers send open messages in order to exchange values.
The number in the command is the AS number of the router to which you want to connect with BGP. The two IP addresses that you use in the neighbor command of the peer routers must be able to reach one another.
If there are any BGP configuration changes, you must reset the neighbor connection to allow the new parameters to take effect. By default, BGP sessions begin with the use of BGP version 4 and negotiate downward to earlier versions, if necessary. This section provides an example of the information that the show ip bgp neighbors command displays. The remote router ID This number is the highest IP address on the router or the highest loopback interface, if existent. The use of a loopback interface to define neighbors is common with iBGP, but is not common with eBGP. If you use the IP address of a loopback interface in the neighbor command, you need some extra configuration on the neighbor router.
In some cases, a Cisco router can run eBGP with a third-party router that does not allow direct connection of the two external peers.
The example in the eBGP Multihop (Load Balancing) section shows how to achieve load balancing with BGP in a case where you have eBGP over parallel lines.
When you apply route map MYMAP to incoming or outgoing routes, the first set of conditions are applied via instance 10. Now, if the match criteria are met and you have a permit, there is a redistribution or control of the routes, as the set action specifies. If the match criteria are met and you have a deny, there is no redistribution or control of the route. If the match criteria are not met and you have a permit or deny, the next instance of the route map is checked. Now that you feel more comfortable with how to start BGP and how to define a neighbor, look at how to start the exchange of network information. The network command works if the router knows the network that you attempt to advertise, whether connected, static, or learned dynamically. This document has discussed how you can use different methods to originate routes out of your AS. For example, assume that AS200, from the example in this section, has a direct BGP connection into AS100.
After BGP receives updates about different destinations from different autonomous systems, the protocol must choose paths to reach a specific destination. BGP bases the decision on different attributes, such as next hop, administrative weights, local preference, route origin, path length, origin code, metric, and other attributes.
The BGP next hop attribute is the next hop IP address to use in order to reach a certain destination. For eBGP, the next hop is always the IP address of the neighbor that the neighbor command specifies. Take special care when you deal with multiaccess and nonbroadcast multiaccess (NBMA) networks. If the common medium to RTA, RTC, and RTD is not multiaccess, but NBMA, further complications occur.
The problem is that RTA does not have a direct permanent virtual circuit (PVC) to RTD and cannot reach the next hop. For situations with the next hop, as in the BGP Next Hop (NBMA) example, you can use the next-hop-self command.
The next-hop-self command allows you to force BGP to use a specific IP address as the next hop.
Synchronization states that, if your AS passes traffic from another AS to a third AS, BGP should not advertise a route before all the routers in your AS have learned about the route via IGP. Routes with a higher weight value have preference when multiple routes to the same destination exist. Local preference is an indication to the AS about which path has preference to exit the AS in order to reach a certain network. Unlike the weight attribute, which is only relevant to the local router, local preference is an attribute that routers exchange in the same AS.
You set local preference with the issue of the bgp default local-preference value command. The bgp default local-preference command sets the local preference on the updates out of the router that go to peers in the same AS. Unless a router receives other directions, the router compares metrics for paths from neighbors in the same AS. In this example, the AS-Path comparison on RTA by command bgp bestpath as-path ignore is ignored.
Assume that you have set the metric that comes from RTC to 120, the metric that comes from RTD to 200, and the metric that comes from RTB to 50. In order to force RTA to compare the metrics, you must issue the bgp always-compare-med command on RTA. With these configurations, RTA picks RTC as next hop, with consideration of the fact that all other attributes are the same.
You can also set metric during the redistribution of routes into BGP if you issue the default-metric number command. The community attribute is a transitive, optional attribute in the range of 0 to 4,294,967,200.
With the ip bgp-community new-format global configuration command, the community value displays in AA:NN format.
A number of different filter methods allow you to control the send and receive of BGP updates. In order to restrict the routing information that the router learns or advertises, you can filter BGP with the use of routing updates to or from a particular neighbor.
The use of access lists is a bit tricky when you deal with supernets that can cause some conflicts. Refer to How to Block One or More Networks From a BGP Peer for sample configurations on how to filter networks from BGP peers. You can specify an access list on both incoming and outgoing updates with use of the BGP AS paths information. The access-list 1 command in this example forces the denial of any updates with path information that starts with 200 and ends with 200. In order to check if you have implemented the correct regular expression, issue the show ip bgp regexp regular-expression command. The _ matches a comma (,), left brace ({), right brace (}), the start of the input string, the end of the input string, or a space.
Refer to Using Regular Expressions in BGP for sample configurations of regular expression filtering.
In this example, you want RTB to set the community attribute to the BGP routes that RTB advertises such that RTC does not propagate these routes to the external peers. When RTC gets the updates with the attribute NO_EXPORT, RTC does not propagate the updates to external peer RTA. Traditional IP communication allows a host to send packets to a single host (unicast transmission) or to all hosts (broadcast transmission). IP multicast is a bandwidth-conserving technology that reduces traffic by simultaneously delivering a single stream of information to potentially thousands of corporate recipients and homes.
IP multicast delivers application source traffic to multiple receivers without burdening the source or the receivers while using a minimum of network bandwidth. Many alternatives to IP multicast require the source to send more than one copy of the data. In the example shown in Figure 1, the receivers (the designated multicast group) are interested in receiving the video data stream from the source. The Internet Assigned Numbers Authority (IANA) controls the assignment of IP multicast addresses.
Note The Class D address range is used only for the group address or destination address of IP multicast traffic. Network protocols use these addresses for automatic router discovery and to communicate important routing information. IP addresses reserved for IP multicast are defined in RFC 1112, Host Extensions for IP Multicasting.
Historically, network interface cards (NICs) on a LAN segment could receive only packets destined for their burned-in MAC address or the broadcast MAC address. One method to accomplish this is to map IP multicast Class D addresses directly to a MAC address.
The IEEE LAN specifications made provisions for the transmission of broadcast and multicast packets. IP multicast makes use of this capability to send IP packets to a group of hosts on a LAN segment. This allocation allows for 23 bits in the Ethernet address to correspond to the IP multicast group address. Because the upper five bits of the IP multicast address are dropped in this mapping, the resulting address is not unique. IGMP is used to dynamically register individual hosts in a multicast group on a particular LAN.
RFC 1112, Host Extensions for IP Multicasting, describes the specification for IGMP Version 1 (IGMPv1). Hosts send out IGMP membership reports corresponding to a particular multicast group to indicate that they are interested in joining that group. Block of fields containing information regarding the sender's membership with a single multicast group on the interface from which the report was sent. IGMPv3 supports applications that explicitly signal sources from which they want to receive traffic. The default behavior for a Layer 2 switch is to forward all multicast traffic to every port that belongs to the destination LAN on the switch.
Three methods efficiently handle IP multicast in a Layer 2 switching environmenta€”Cisco Group Management Protocol (CGMP), IGMP Snooping, and Router-Port Group Management Protocol (RGMP).
CGMP is a Cisco-developed protocol that allows Catalyst switches to leverage IGMP information on Cisco routers to make Layer 2 forwarding decisions. The switch receives this CGMP join message and then adds the port to its content-addressable memory (CAM) table for that multicast group. Because IGMP control messages are sent as multicast packets, they are indistinguishable from multicast data at Layer 2. CGMP and IGMP Snooping are IP multicast constraining mechanisms designed to work on routed network segments that have active receivers.
Switched Ethernet backbone network segments typically consist of several routers connected to a switch without any hosts on that segment.
Multicast-capable routers create distribution trees that control the path that IP multicast traffic takes through the network in order to deliver traffic to all receivers. The simplest form of a multicast distribution tree is a source tree with its root at the source and branches forming a spanning tree through the network to the receivers. The (S, G) notation implies that a separate SPT exists for each individual source sending to each groupa€”which is correct. Unlike source trees that have their root at the source, shared trees use a single common root placed at some chosen point in the network. In this example, multicast traffic from the sources, Hosts A and D, travels to the root (Router D) and then down the shared tree to the two receivers, Hosts B and C. Members of multicast groups can join or leave at any time; therefore the distribution trees must be dynamically updated.
Source trees have the advantage of creating the optimal path between the source and the receivers. In unicast routing, traffic is routed through the network along a single path from the source to the destination host. In multicast forwarding, the source is sending traffic to an arbitrary group of hosts that are represented by a multicast group address. PIM uses the unicast routing information to create a distribution tree along the reverse path from the receivers towards the source. When a multicast packet arrives at a router, the router performs an RPF check on the packet. PIM is IP routing protocol-independent and can leverage whichever unicast routing protocols are used to populate the unicast routing table, including Enhanced Interior Gateway Routing Protocol (EIGRP), Open Shortest Path First (OSPF), Border Gateway Protocol (BGP), and static routes. Routers accumulate state information by receiving data streams through the flood and prune mechanism.
PIM-SM distributes information about active sources by forwarding data packets on the shared tree.
Sources register with the RP and then data is forwarded down the shared tree to the receivers. If the shared tree is not an optimal path between the source and the receiver, the routers dynamically create a source tree and stop traffic from flowing down the shared tree. PIM-SM was originally described in RFC 2362, Protocol Independent Multicast-Sparse Mode (PIM-SM): Protocol Specification. Bidirectional PIM (bidir-PIM) is an enhancement of the PIM protocol that was designed for efficient many-to-many communications within an individual PIM domain. In bidirectional mode, traffic is routed only along a bidirectional shared tree that is rooted at the RP for the group. Bidir-PIM is derived from the mechanisms of PIM sparse mode (PIM-SM) and shares many of the shared tree operations. PGM is a reliable multicast transport protocol for applications that require ordered, duplicate-free, multicast data delivery from multiple sources to multiple receivers. PGM is intended as a solution for multicast applications with basic reliability requirements. You can find the current specification for PGM in RFC 3208, PGM Reliable Transport Protocol Specification.
The following topics represent interdomain multicast protocolsa€”meaning, protocols that are used between multicast domains.
MBGP provides a method for providers to distinguish which route prefixes they will use for performing multicast RPF checks. The main advantage of MBGP is that an internetwork can support noncongruent unicast and multicast topologies.
In the PIM sparse mode model, the router closest to the sources or receivers registers with the RP.
The RP in each domain establishes an MSDP peering session using a TCP connection with the RPs in other domains or with border routers leading to the other domains.
Anycast RP is a useful application of MSDP that configures a multicast sparse mode network to provide for fault tolerance and load sharing within a single multicast domain. Now that we have covered subnetting to create just two networks and moved on to creating multiple subnets with Class B and Class A networks, let’s finalize this blog series topic with one more installment. This can be stated in words: Take the number two and raise it to the power of the number of host bits, then subtract two from the result.
Thus we see the five host bits that we reserved, which means the other three bits are converted to ones, or network bits.
This same strategy can be employed whether we are starting with a Class B or Class A network as well.
A typical problem of this nature usually begins with how much of a network is available from which further subnets can be created. The objective is to meet the IP addressing needs of this scenario while being as efficient as possible with our available address space.
Let’s attack this problem the way we have been solving the previous problems; that is, fold our piece of the network to match the number of required numbers. Since there were four bits borrowed that were added to the original sixteen network bits, we realize the borrowed bits carry into the third octet. We now have networks which meet the needs of 100 users, 50 users, and 25 users respectively.
The valid host IP addresses are the actual addresses that will be placed on the router interfaces. If you imagine your entire available network address space as a whole pie, then it helps to see how these individual slices we have made might look.
If you decide to continue creating your point-to-point links from where you left off instead of putting them at the top end of your network, you would just start with the .224 and do three networks with an increment of four. Once you master this folding technique, you will approach certification exams, and real world subnetting, with a completely different attitude. A  How do you determine the interesting octet if you have a Class B network and you borrow eight bits, or a Class A network where you borrow eight bits or sixteen bits? International Shipping - items may be subject to customs processing depending on the item's declared value. Your country's customs office can offer more details, or visit eBay's page on international trade. Estimated delivery dates - opens in a new window or tab include seller's handling time, origin ZIP Code, destination ZIP Code and time of acceptance and will depend on shipping service selected and receipt of cleared payment - opens in a new window or tab. This item will be shipped through the Global Shipping Program and includes international tracking.
Will usually ship within 1 business day of receiving cleared payment - opens in a new window or tab. Cisco IT now provides permanent IPv6 Internet presence and is well on the way toward ubiquitous IPv6 network access. At Cisco, the network connects people to people, people to devices such as sensors, and devices to devices. The confluence of people, process, data, and things, known as the Internet of Everything (IoE), is helping to increase asset utilization, improve productivity, create efficiencies in the supply chain, enhance the customer experience, and foster innovation.
An ancillary benefit of unlimited global addressing is eliminating the need for hardware and software to perform Network Address Translation (NAT) from IPv4 to IPv6. Cisco IT has been planning and executing the integration of IPv6 into the IT infrastructure since 2002, balancing the effort with other IT priorities such as cloud computing, data center virtualization, and continuing adoption of Cisco TelePresence® and other collaboration technologies. The transition to IPv6 affects the entire enterprise network, which connects 450 Cisco offices in 90 countries.
Cisco IT's journey to IPv6 can be viewed in two stages: a gradual effort from 2002-2010, and then an accelerated effort beginning in 2010, as IPv4 address exhaustion became imminent (Figure 1). In 2002, development and testing of IPv6 features in Cisco® routers and switches were well under way. Cisco IT carefully planned how to allocate the address space to different geographies, following the same principles that the company had used for IPv4 addresses.
To manage the IPv6 address space, Cisco IT modified a dedicated web-based application to support IPv6 and added support for IPv6 in the company's domain name system (DNS) services.
After developing the IPv6 address plan, Cisco IT turned its attention to developing a lightweight solution to provide IPv6 connectivity for labs, engineering teams, and Cisco headquarters in San Jose, California. Intra-Site Automatic Tunnel Addressing Protocol (ISATAP), and these tunnels terminated on the same router as the 6in4 tunnels.
The first step was to form a cross-functional team to agree on goals for IPv6 integration and migration. The team developed two strategies, executed in parallel, to integrate IPv6 into the global Cisco network.
As the first step, Cisco IT engaged Cisco Services to provide IPv6 readiness support through the Cisco Network Optimization Service. Referring to the reports, the team first determined if the hardware platform supported basic IPv6 functions. If the hardware was IPv6-capable, Cisco IT determined whether the Cisco IOS® Software version supported IPv6. The following paragraphs describe the steps that Cisco IT took to develop an IPv6 web presence. Held on June 8, 2011, World IPv6 Day was a one-day global event to test global readiness for IPv6. No major issue occurred during World IPv6 Day, and the event was widely regarded as a success for Cisco and the industry at large. The target state for Cisco IT's web presence is an end-to-end dual-stack design that extends IPv4 and IPv6 connectivity all the way to the web servers. Architectural elements for the Cisco IPv6 Internet presence include a reverse proxy, dual-stack production network, DNS and name resolution, content delivery service, web analytics system, availability and performance monitoring, and security.
Cisco IT uses the same name-resolution process used previously for the IPv4-only web presence. To provide name resolution in a dual-stack environment, Cisco IT added support for AAAA records into Cisco GSS and the CDN provider network. Cisco IT's web team worked with the CDN provider to make sure the provider could support downloads to IPv6 clients, with an experience comparable to the IPv4 client experience. The team continues to use the same web analytics system used when the web presence was IPv4 only. The web team is adding IPv6 support to applications in other web server environments one by one. To monitor availability and performance of web services from outside the enterprise, Cisco IT works with its existing vendor, which connects from many points on the Internet and reports how long it takes to load pages.
When Cisco IT first embarked on its journey to IPv6, most IPv6 service providers provided IPv6-over-IPv4 tunnels. Initially, the service providers installed temporary IPv6 Internet circuits that were physically separate from production circuits. In parallel with introducing an IPv6 Internet presence, Cisco IT worked to provide access from IPv6-enabled devices from anywhere on the Cisco global network.
In the original design, all 6in4 and ISATAP tunnels terminated at a single hub at San Jose headquarters. When preparing for World IPv6 Day in 2011, Cisco IT began upgrading the core links to support dual-stack traffic, starting with the heavily trafficked core links connecting San Jose and Bangalore. To avoid incremental costs for integrating IPv6 into the network, Cisco IT implemented IPv6-capable hardware and software through the Fleet Upgrade Program.
Cisco IT used Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv4 and continues using it today, with the dual-stack network.
Since 2003, Cisco users have had the option of turning on ISATAP to acquire IPv6 connectivity through an Anycast regional ISATAP router. More recently, Cisco IT began providing native IPv6 support through a dual-stack network in dozens of global sites. To identify internal and third-party tools and processes that needed updates to support IPv6, Cisco IT conducted a Fault, Configuration, Accounting, Performance, and Security (FCAPS) evaluation.
Cisco IT engaged Cisco Services for IPv6 design reviews, software version recommendations, security recommendations, and testing.
If an application is started by dialing a phone number, it must have a CM Telephony Trigger. The Unified CCX system looks for an available CTI Port in the CM Telephony Call Control Group assigned to the Trigger. Unified CCX accepts the call on the CTI Port, the call rings on the CTI Port, and a Unified CCX script decides how to handle the call. Why does the CM Telephony Trigger need to have Primary and or Secondary Dialogue Groups assigned to it?
In Unified CCE, when a Unified ICME system sends a Connect request to the Unified CCX system to send a queued call to a destination label. The figure below shows a simplified block diagram of a contact flow outside of Unified CCE. Unified CCX receives the contact signal at the phone number trigger point or the Web address trigger point. If the contact is a call, then the Unified CCX system looks for a CTI port in the CM Telephony Call Control Group assigned to the trigger (the phone number).
If the contact is a Web connection, then the Unified CCX system looks for a CTI port in the HTTP Control Group assigned to the trigger (the URL).
The script determines how to handle the call: The Unified CCX script can Redirect the call (for example, when no agents are available). Unified CCX scripts can direct calls based on various criteria, such as time of day or the availability of subsystems. When integrated in a Unified CCE environment, Unified CCX can be used in two different ways depending on the call flow. You can define your Applications as either post-routing or translation-routing applications. This scenario represents a call that is queued in the Unified IP IVR system through Post Routing until an agent becomes available.
The caller dials the desired phone number (an application Trigger that is a Unified CCX Route Point). The Unified CCX system looks for a CTI port in the CM Telephony Call Control Group assigned to the trigger (the phone number). The Unified CCX system determines which CTI Port to take the call on and sends a redirect request to Unified CM through the CM Telephony protocol. In most post-routing cases, the script will welcome the caller and collect some information from the caller to be sent over to the Unified ICME system. Since this is a post-routing application, once the End step is reached, the Unified CCX system requests instruction from the Unified ICME system.
The Unified ICME system will have an ICM script configured to run for this routing client DN.
The ICM script will determine how to handle the call and will instruct the Unified CCX system accordingly. The Unified CCX system responds to the commands from the Unified ICME system until the Unified ICME system signals that the call is complete.
This scenario represents a call that is queued in the Unified IP IVR through Translation Routing until an agent becomes available. The caller dials the desired phone number (an application Trigger that is a Unified ICME Route Point). The caller is translation routed to the Unified IP IVR by the PG (the ICM Peripheral Gateway) sending a redirect request to CTI through CM Telephony. The Unified CCX system determines which CTI Port to take the call on and sends a redirect request to through CM Telephony.
The Unified CCX system accepts the call, starts a session with the ICM PG, and sends a REQUEST_INSTRUCTION request. The Unified CCX system maps the requested VRU script name to a Unified CCX Script based on the VRU Script configuration in the Unified CCX system. If the Unified CCX script answers the call, and the trigger has been assigned a Dialogue Group, it establishes a media connection with the caller. When the script ends, it sends a RUN_SCRIPT_ RESULT message back to the Unified ICME system. Once an agent becomes available, the Unified ICME system sends a CANCEL message to the Unified CCX system. The Unified ICME system then sends a CONNECT message that includes the Agent's extension as the Label. The ICM subsystem of the Unified CCX system allows Unified IP IVR to interact with the ICM system. The Service Control interface allows the Unified ICME system to provide call-processing instructions to the Unified IP IVR system. The Service Control Interface is enabled from the Unified CCX ICM subsystem configuration web page. Normal The Normal label is a character string that encodes the instructions for routing the call.
Ring No Answer The Ring No Answer (RNA) label indicates that the caller should receive an RNA treatment.
Default The Default label indicates that the Unified IP IVR system should run the default script.
The scripts that control Unified IP IVR calls have a VRU Script name in the Unified ICME system that must be properly mapped to a Unified CCX script name (.aef file) in the Unified CCX system. Data is passed back and forth between the Unified ICME system and the Unified CCX scripts using Expanded Call Variables.
One function that can prove useful is the ability to use the Unified ICME RUN_SCRIPT node with a name that includes parameter separators.
When you use parameter separators in Unified CCX, the Unified ICME script name must include the parameter as part of its name. For more information on script parameters, see the Cisco Unified Contact Center Express Editor Step Reference Guide and the Cisco Unified Contact Center Express Getting Started with Scripts Guide.
The SS_TEL or SS_SIP (Telephony subsystems) debug traces can be used to debug the CM Telephony aspect of a call.
When debugging Unified ICME problems in the Unified IP IVR system, turn on the ICM related debugs. The DNs (Dialed Numbers) of the Route Points, that is, the triggers that you configure in the Unified CCX system are used in the Unified ICME system as Translation Route DNIS'. The CTI port group number IDs in Unified CCX must have the same numbers as the peripheral trunk group numbers in the Unified ICME system. It is imperative that the script name referenced in your Unified ICME Run External Script node matches what is configured in the VRU Script List configuration in the ICM Subsystem on Unified CCX.
In order to eliminate any confusion, it is highly recommended that you name the Unified CCX script exactly the same in all places.
The VRU Script Name column on the left is the name that Unified ICME will refer to when calling the script and the Script column on the right is the file name of the Unified CCX script you want to run when Unified ICME calls the script mentioned in the VRU Script Name column. As you can imagine, if you refer to these scripts by different names in Unified ICME and Unified CCX, it can become confusing when it comes time to troubleshoot. The VRU connection port numbers in Unified CCX must be the same as the VRU connection port numbers in the Unified ICME system. Any enterprise ECC (Expanded Call Context) variables must be defined on both sides of the system (in Unified IP IVR and in Unified ICME software).

Karthik Kulkarni is a Technical Marketing Engineer at Cisco Data Center Business Group focusing on Big Data and Hadoop technologies.
The authors acknowledge contributions of Ashwin Manjunatha, and Sindhu Sudhir in developing the Cisco UCS Common Platform Architecture Version 2 (CPA v2) for Big Data with Comprehensive Data Protection using Intel Distribution for Apache Hadoop Cisco Validated Design. The CVD program consists of systems and solutions designed, tested, and documented to facilitate faster, more reliable, and more predictable customer deployments. All other trademarks mentioned in this document or website are the property of their respective owners. This document describes the architecture and deployment procedures of Intel Distribution for Apache Hadoop on a 64 node cluster based Cisco UCS Common Platform Architecture Version 2 (CPA v2) for Big Data.
Hadoop has become a strategic data platform embraced by mainstream enterprises as it offers the fastest path for businesses to unlock value in big data while maximizing existing investments.
Intel Distribution for Apache Hadoop software (Intel Distribution) is a software platform that provides distributed data processing and data management for enterprise applications that analyze massive amounts of diverse data. Intel has developed a solution for Big Data that includes a feature enhanced controlled distribution of Apache Hadoop, with optimizations for better hardware performance, and services to streamline deployment and improve the end user experience. This solution provides a foundational platform for Intel to offer additional solutions as the Hadoop ecosystem evolves and expands. Intel's Hadoop solution focuses on efficient integration of Apache Open source based Hadoop software distribution with commodity servers to deliver optimal solutions for a variety of use cases while minimizing total cost of ownership.
Intel Distribution provides security and access control features, each of which can be applied in conjunction with others or independently if needed. ID is optimized for Intel Advanced Encryption Standard New Instructions (AES-NI), a technology that is built into Intel Xeon processors.
Note No changes are required from the configuration point of view for AES-NI encryption optimizations, as mapreduce code which has support for encrypting and decrypting data (that is, the map-reduce code will decrypt data when read from HDFS and encrypt back when writing to HDFS) running on an encrypted workload will automatically trigger the AES-NI.
Kerberos is a network authentication protocol that uses symmetric key cryptography to provide strong authentication for client-server applications. For example, if there is a 16 node cluster where the primary NameNode service runs on node 1 and a datanode service runs on node 5, then the datanode service must pass Kerberos authentication before it is permitted to communicate with the primary NameNode service. For example, if the Unix user jdoe needs to run a MapReduce application, then that user must pass Kerberos authentication before the application is permitted to run. Note Configuration for Kerberos authentication (secure mode) should be done prior to ID setup and necessary keytab files need to be provided during installation process in order to support Kerberos authenticated communication between services and users instead of simple ssh (simple mode). After a user is authenticated, the Apache Hadoop daemon checks if the user is in the ACL or is a part of a group that is in the ACL.
A role is a set of permissions for creating, reading, and modifying data as well as service administration for the following Apache Hadoop services. Note Configuration for Integration with Identity Store for Access control is done after ID setup. Hive is the query engine framework for Intel Hadoop that facilitates easy data summarization, ad-hoc queries, and the analysis of large datasets stored in HDFS and HBase. Pig is a platform for analyzing large data sets that consists of a high-level language for expressing data analysis programs, coupled with infrastructure for evaluating these programs. Note This CVD describes the installation process for a 64-node Performance and Capacity Balanced Cluster configuration. Figure 2 illustrates the ports on the Cisco Nexus 2232PP fabric extender connecting to the Cisco UCS C240M3 servers.
Figure 3 illustrates the port connectivity between the Cisco Nexus 2232PP FEX and the Cisco UCS C240M3 server.
This section provides details for configuring a fully redundant, highly available Cisco UCS 6296 Fabric Interconnect. This section describes the steps to perform the initial setup of the Cisco UCS 6296 Fabric Interconnects A and B. A LGV HOST oferece aos seus clientes a nova geraA§A?o de hosting com os planos mais completos do mercado.
Servidores com 1Gbps de banda e trA?fego totalmente ilimitado em toda nossa rede sem qualquer custo adicional. Segue abaixo os equipamentos que utilizamos em nossa infraestrutura, suas devidas capacidades e funA§Aµes. Aqui estA?o algumas das perguntas mais frequentes, quaisquer outras dA?vidas podem ser resolvidas em nossa Base de Conhecimento ou com nossos atendentes, teremos o maior prazer em atende-lo! This information is mainly an indication of the full paths that a route must take in order to reach the destination network.
The TCP connection is essential in order for the two peer routers to start the exchange of routing updates. The values that the routers exchange include the AS number, the BGP version that the routers run, the BGP router ID, and the keepalive hold time. You can prevent negotiations and force the BGP version that the routers use to communicate with a neighbor. Normally, you use the loopback interface to make sure that the IP address of the neighbor stays up and is independent of hardware that functions properly. The neighbor router needs to inform BGP of the use of a loopback interface rather than a physical interface to initiate the BGP neighbor TCP connection. The example is a workaround in order to achieve load balancing between two eBGP speakers over parallel serial lines.
The first instance has a sequence number of 10, and the second has a sequence number of 20.
If the first set of conditions is not met, you proceed to a higher instance of the route map. The match specifies a match criteria, and set specifies a set action if the criteria that the match command enforces are met. This concept is different than the familiar configuration with Interior Gateway Routing Protocol (IGRP) and RIP. The only difference is that BGP considers these routes to have an origin that is incomplete, or unknown. Remember that these routes are generated in addition to other BGP routes that BGP has learned via neighbors, either internal or external. Again, the difference is that the network command adds an extra advertisement for these same networks, which indicates that AS300 is also an origin for these routes.
Is it true that you can do the same thing by learning via eBGP, redistributing into IGP, and then redistributing again into another AS? The BGP speaker that receives the update redistributes the information to other BGP speakers outside of its AS.
The AS_PATH attribute is actually the list of AS numbers that a route has traversed in order to reach a destination. INCOMPLETE usually occurs when you redistribute routes from other routing protocols into BGP and the origin of the route is incomplete. The sections BGP Next Hop (Multiaccess Networks) and BGP Next Hop (NBMA) provide more details. If the common medium is a frame relay or any NBMA cloud, the exact behavior is as if you have connection via Ethernet. For BGP, this network gets the same treatment as a locally assigned network, except BGP updates do not advertise this network. If you do not pass traffic from a different AS through your AS, you can disable synchronization.
If all your routers in the AS run BGP and you do not run IGP at all, the router has no way to know. In the example in this section, all updates that RTD receives are tagged with local preference 200 when the updates reach RTD.
In order for the router to compare metrics from neighbors that come from different ASs, you need to issue the special configuration command bgp always-compare-med on the router.
The commands are the bgp deterministic-med command and the bgp always-compare-med command. It is configured to force BGP to fall on to the next attribute for route comparison (in this case metric or MED).
The community attribute is a way to group destinations in a certain community and apply routing decisions according to those communities. You can filter BGP updates with route information as a basis, or with path information or communities as a basis.
The method uses the distribute-list command with standard and extended access control lists (ACLs), as well as prefix list filtering. With an AS400, as in the diagram in this section, updates that AS400 originates have path information of the form (200, 400).
You wanted path information that comes inside updates to match the string in order to make a decision. This action adds the value 100 200 to any existing community value before transmission to RTC.
The community list allows you to filter or set attributes with different lists of community numbers as a basis. IP multicast provides a third possibility: allowing a host to send packets to a subset of all hosts as a group transmission. Applications that take advantage of multicast include video conferencing, corporate communications, distance learning, and distribution of software, stock quotes, and news. Multicast packets are replicated in the network at the point where paths diverge by Cisco routers enabled with Protocol Independent Multicast (PIM) and other supporting multicast protocols, resulting in the most efficient delivery of data to multiple receivers. Some, such as application-level multicast, require the source to send an individual copy to each receiver. The receivers indicate their interest by sending an Internet Group Management Protocol (IGMP) host report to the routers in the network. A multicast group is an arbitrary group of receivers that expresses an interest in receiving a particular data stream. SSM is an extension of the PIM protocol that allows for an efficient data delivery mechanism in one-to-many communications.
These addresses are described in RFC 2365, Administratively Scoped IP Multicast, to be constrained to a local group or organization. In IP multicast, several hosts need to be able to receive a single data stream with a common destination MAC address.
Today, using this method, NICs can receive packets destined to many different MAC addressesa€”their own unicast, broadcast, and a range of multicast addresses. In the 802.3 standard, bit 0 of the first octet is used to indicate a broadcast or multicast frame.
The mapping places the lower 23 bits of the IP multicast group address into these available 23 bits in the Ethernet address (see Figure 3). In fact, 32 different multicast group IDs map to the same Ethernet address (see Figure 4). By intradomain multicasting protocols, we mean the protocols that are used inside of a multicast domain to support multicasting. The host will receive traffic only from sources whose IP addresses are not listed in the EXCLUDE list. This behavior reduces the efficiency of the switch, whose purpose is to limit traffic to the ports that need to receive the data. All subsequent traffic directed to this multicast group will be forwarded out the port for that host. A switch running IGMP Snooping must examine every multicast data packet to determine if it contains any pertinent IGMP control information.
They both depend on IGMP control messages that are sent between the hosts and the routers to determine which switch ports are connected to interested receivers.
Because routers do not generate IGMP host reports, CGMP and IGMP Snooping will not be able to constrain the multicast traffic, which will be flooded to every port on the VLAN. The two basic types of multicast distribution trees are source trees and shared trees, which are described in the following sections. Because this tree uses the shortest path through the network, it is also referred to as a shortest path tree (SPT). When all the active receivers on a particular branch stop requesting the traffic for a particular multicast group, the routers prune that branch from the distribution tree and stop forwarding traffic down that branch. This advantage guarantees the minimum amount of network latency for forwarding multicast traffic. This advantage lowers the overall memory requirements for a network that only allows shared trees. A unicast router does not consider the source address; it considers only the destination address and how to forward the traffic toward that destination. The multicast router must determine which direction is the upstream direction (toward the source) and which one is the downstream direction (or directions). The multicast routers then forward packets along the distribution tree from the source to the receivers. The router looks up the source address in the unicast routing table to determine if the packet has arrived on the interface that is on the reverse path back to the source.
If the packet has arrived on the interface leading back to the source, the RPF check succeeds and the packet is forwarded. These data streams contain the source and group information so that downstream routers can build up their multicast forwarding table. Only network segments with active receivers that have explicitly requested the data will receive the traffic.
Because PIM-SM uses shared trees (at least, initially), it requires the use of a rendezvous point (RP). The edge routers learn about a particular source when they receive data packets on the shared tree from that source through the RP.
Multicast groups in bidirectional mode can scale to an arbitrary number of sources with only a minimal amount of additional overhead.
This means that a source tree must be created to bring the data stream to the RP (the root of the shared tree) and then it can be forwarded down the branches to the receivers. In bidir-PIM, the IP address of the RP acts as the key to having all routers establish a loop-free spanning tree topology rooted in that IP address. Data from the source can flow up the shared tree (*, G) towards the RP and then down the shared tree to the receiver. Bidir-PIM also has unconditional forwarding of source traffic toward the RP upstream on the shared tree, but no registering process for sources as in PIM-SM. PGM guarantees that a receiver in a multicast group either receives all data packets from transmissions and retransmissions or can detect unrecoverable data packet loss. The source maintains a transmit window of outgoing data packets and will resend individual packets when it receives a negative acknowledgment (NAK).
The RPF check is the fundamental mechanism that routers use to determine the paths that multicast forwarding trees will follow and to successfully deliver multicast content from sources to receivers. Because MBGP is an extension of BGP, it contains the administrative machinery that providers and customers require in their interdomain routing environment, including all the inter-AS tools to filter and control routing (for example, route maps).
These new attributes create a simple way to carry two sets of routing informationa€”one for unicast routing and one for multicast routing. When the unicast and multicast topologies are congruent, MBGP can support different policies for each.
ISPs did not want to rely on an RP maintained by a competing ISP to provide service to their customers. When the RP learns about a new multicast source within its own domain (through the normal PIM register mechanism), the RP encapsulates the first data packet in a Source-Active (SA) message and sends the SA to all MSDP peers. Our goal in this blog is twofold: 1) Discuss subnetting a subnet and 2) discover how to use the folding method to solve situations seeking a desired number of hosts per subnet. The first thing to realize is that our folding method can still be used to solve this problem. Just make sure to preserve the required number of host bits to meet the requirements, and then create a subnet mask in binary that HAS that number of host bits. Using our strategy from the first part of this blog tells us we can double until we have counted nine fingers, two, four, eight, …until we get to 512.
This is a topic you are expected to know in order to pass the ICND-2 test, or the Composite Exam. Good design strategy (although this is not absolutely required) is to put the point-to-point networks at the top end of the network range. A mask of 252 gives us an increment of four, and it is the fourth octet that is interesting. Although figure 1.1 is not exactly to scale, it does help us see what happens as we move our subnet mask bits to match the needs of the network design. I often say that once this all makes sense, you will hope for an exam where every question is a subnetting question. Please keep in mind however, that all comments are moderated according to our comment policy, and all links are nofollow.
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This posed a challenge at Cisco because the Internet Assigned Numbers Authority (IANN) handed out its last IPv4 address block to the five regional Internet registries on January 31, 2011. That number equates to billions and billions of addresses for every square meter on the planet, supporting the Internet of Everything. More than 180,000 people connect to the Cisco corporate network, including 68,000 employees, 20,000 channel partners, more than 100 application service providers, and approximately 200 development partners.
The corporate network needed to support IPv6 for lab-to-lab testing and to allow developers and test engineers to connect from their desktops to the labs.
ARIN gave Cisco the same type of address space that Internet service providers use because Provider Independent (PI) space was not yet available. To implement the solution quickly, the team decided to use 6in4 tunnels as a transition technology. Anticipating customers' needs, Cisco product development teams began accelerating product support for IPv6, providing the same functions available with IPv4.
One track was to develop an IPv6 Internet presence, making public content, services, and applications available to customers, partners, and employees connecting with IPv6 devices. If it did not, Cisco IT replaced the hardware through the normal Fleet Management Program, Cisco IT's infrastructure lifecycle management program. The goal was to give the web team hands-on experience with IPv6 without placing public-facing content and services at risk. The goal was for content providers and network operators to turn on IPv6 and leave it on permanently. To gain visibility into the user experience for customers and partners outside the United States, the team used a third-party web analytics tool with dual-stack support to analyze NetFlow v9 information. In Figure 9, the left side shows the design for World IPv6 Day, the middle shows the design for World IPv6 Launch, and the right side shows the target state.
One was that the relative ease of implementation would help the team make the deadline to participate in the World IPv6 Launch. The web server farm has virtual IPv6 and IPv4 addresses hosted on the reverse proxy, while the physical web servers have an IPv4 address only. Cisco IT configured the Internet Point of Presence (iPoP), DMZ, and data center networks for dual-stack support, allowing IPv6 traffic to flow from the Internet to the 6to4 proxy. The CDN provider inserts the IPv6 source address when proxying HTTP requests back to the origin.
The team made a few changes at the application layers to accommodate IPv6 and the proxy-based design. For each application, the team first makes sure that it can monitor availability and performance over IPv4 only, IPv4 and IPv6, and IPv6 only. As services providers begun offering dual-stack services, Cisco IT worked with its existing service providers to plan the transition.
Later, the providers decommissioned the temporary circuits and deployed production dual-stack circuits, still in use. But as engineering groups accelerated IPv6 product development and testing, backhauling all traffic to San Jose began to degrade performance.
In the upgraded parts of the network, all network services, including quality of service (QoS) and multicast, apply to both IPv4 and IPv6. This approach gave Cisco IT the confidence to extend IPv6 into the core, because the team knew that they could fall back to IPv4 if something did not work as expected. Early in the IPv6 transition project, the design team updated the design standards for the Fleet Upgrade Program to include IPv6 requirements.
The program started with the wired network and then expanded to wireless networks in conjunction with the Fleet Upgrade Program. Employees were told that a building supported IPv6 only after the client services team provided an approved build. At the outset, monitoring was limited to 6in4 tunnels to regional headends and a small number of IPv6-enabled devices. The Operations Command Center (OCC) management and escalation process has remained the same, and the team supports the same SLA for IPv6 and IPv4 devices.
In these offices, employees and contractors can access hosts and applications that have an IPv6 address. The application can be a workflow application, a CM Telephony application, (and in a Unified CCE system) an ICM Translation Routing application or an ICM Post-Routing application. Once the Unified CCX system requests a Redirect and Unified CM accepts it, the redirecting CTI Port is released and returned to the idle port list. Obtain Header Information, Parameters, Cookies and Environment Attributes and assign them to local variables.
When configuring Unified CCX in the Unified CCX Administration web page, you must enter the information that Unified CCX uses to configure CTI Ports and Route Points in Unified CM. When configuring Unified CCX, you define a CM Telephony User Prefix that is used to create the CM Telephony User in the Unified CM. Redirects are performed when a call comes and the call is sent from the route point to the designated CTI port (in this case, the redirect takes place internally as part of the protocol), when a Unified CCX script executes a call Redirect step, or when a Unified ICME system sends a Connect request to the Unified CCX system to send a queued call to a destination label.
Unlike the redirect that the Route Point does to the CTI Port (which is not configurable), the CSS used for a redirect for a call that is already established on a CTI Port is indeed controlled by the Redirect Calling Search Space parameter in the Call Control Group config.
Calling search spaces (CSS) determine the partitions that calling devices, including IP phones, SIP phones, and gateways, can search when attempting to complete a call.
Regions determine the maximum bandwidth codec that is allowed for calls both intra- and inter-region, not the codec itself. Otherwise, calls across the WAN are forced to G.729 in the region configuration, which causes the call to fail if there are no hardware transcoding resources properly configured and available.
In the event that one or more of the devices are in a location, if sufficient bandwidth is not available, the requested call-control operation will fail. When you create a region, you specify the codec that can be used for calls between devices within that region, and between that region and other regions. Unified ICME provides a central control system that directs calls to various human and automated systems, such as Integrated Voice Response (IVRs) units [also called Voice Response Units (VRUs)] and Automatic Call Distribution (ACD) systems. When used with Unified ICME in a Translation Routing or Post Routing Application, the Unified IP IVR system does not make decisions as to what script to run.
The Unified ICME system sends the connect message with a label to instruct the Unified IP IVR system where to direct the call. If the calls will first traverse through the Unified IP IVR and then through Unified CCE, it is considered a Post-Routing scenario. If Unified CCE first has control of the call and it needs to flow through the Unified IP IVR, it is considered a Translation-Routing scenario. In a Unified CCE environment, the Unified ICME software is the primary controller of all calls. This instruction is a route request with the VRU peripheral as the routing client and the Unified CCX Route Point as the DN. ICM scripts are composed of many different call-handling steps, including the following four commands it can send to the Unified CCX system-connect, Release, Run VRU Script, and Cancel. For example, the ICM script could send a Run VRU Script request to the Unified IP IVR system, instructing the Unified IP IVR system to run a script that plays music and thanks the caller for their patience.
The ICM subsystem of Unified CCX uses a proprietary protocol to communicate with the ICM PG. It also provides the Unified ICME system with event reports indicating changes in call state. It contains either a directory number to which the Unified IP IVR system should route the call or the name of a .wav file representing an announcement.
Unless you set up a Busy label port group to handle the call, the Unified IP IVR system generates a simulated busy signal from a .wav file until the caller hangs up. Unless you set up a Ring No Answer label port group to handle the call, the Unified IP IVR system generates a simulated ringing sound from a .wav file until the caller hangs up. The Parameter Separator is defined from the Unified CCX ICM subsystem configuration web page.
Within that script, you can have multiple branches that would execute based on the value of a parameter that is passed by the Unified ICME system.
This example allows the variable param1 to be tested and for the script to take the desired branch based on its value.
The use of the word partner does not imply a partnership relationship between Cisco and any other company. The intended audience of this document includes, but is not limited to, sales engineers, field consultants, professional services, IT managers, partner engineering and customers who want to deploy Intel Distribution for Apache Hadoop on the Cisco UCS CPA v2 for Big Data.
The Intel Distribution for Apache Hadoop is a 100% open source distribution of Apache Hadoop that is truly enterprise grade having been built, tested and hardened with enterprise rigor.
It has been widely adopted for finance, healthcare, service provider, entertainment, insurance, and public-sector environments.
Deployed in redundant pairs, Cisco fabric interconnects offer the full active-active redundancy, performance, and exceptional scalability needed to support the large number of nodes that are typical in clusters serving Big Data applications. 24 Small Form Factor (SFF) disk drives are supported in performance optimized option and 12 Large Form Factor (LFF) disk drives are supported in capacity option, along with 4 Gigabit Ethernet LAN-on-motherboard (LOM) ports. Optimized for virtualized networking, these cards deliver high performance and bandwidth utilization and support up to 256 virtual devices.
It makes the system self-aware and self-integrating, managing the system components as a single logical entity.
The Intel Distribution includes Apache Hadoop and other software components with enhancements from Intel.
Encryption and decryption are compute-intensive processes that traditionally add considerable latency and consume substantial processing resources.
The protocol requires mutual authentication, which means the client and the server must verify one another's identity before the client is permitted to use resources on the server.
These steps are detailed in ID Installation as prerequisite steps if we are choosing secure mode.
Authorization is the process of determining whether an authenticated identity is entitled to use a particular resource.
Apache Hadoop authenticates a user based on the username in the Unix Shell, if in simple mode, or the user's Kerberos principal, if in secure mode. If either condition is true, then the user is authorized to perform the action or actions controlled by the ACL. When a role is assigned to a LDAP group, any user in that group gains the set of permissions that the role consists of. With SQL like semantics, Hive makes it easy for RDBMS users to transition into querying unstructured data in Hadoop. The salient property of Pig programs is that their structure is amenable to substantial parallelization, which in turns enables them to handle very large data sets. Review the settings that were printed to the console, and enter yes to save the configuration. The installer detects the presence of the partner fabric interconnect and adds this fabric interconnect to the cluster.
Routers in an AS can use multiple Interior Gateway Protocols (IGPs) to exchange routing information inside the AS. After the confirmation and acceptance of these values, establishment of the neighbor connection occurs.
The extended ping forces the pinging router to use as source the IP address that the neighbor command specifies. The remote AS number points to either an external or an internal AS, which indicates either eBGP or iBGP. A version that continues to increment indicates that there is some route flap that causes the continuous update of routes. In the case of eBGP, peer routers frequently have direct connection, and loopback does not apply.
In this case, RTA must force BGP to use the loopback IP address as the source in the TCP neighbor connection.
Refer to Sample Configuration for iBGP and eBGP With or Without a Loopback Address for a complete network scenario sample configuration. The eBGP multihop allows a neighbor connection between two external peers that do not have direct connection. In normal situations, BGP picks one of the lines on which to send packets, and load balancing does not happen.
The control and modification of routing information occurs through the definition of conditions for route redistribution from one routing protocol to another.
The sequence number is simply an indication of the position that a new route map is to have in the list of route maps that you have already configured with the same name. This next-instance check continues until you either break out or finish all the instances of the route map.
If there is no match, you proceed down the route map list, which indicates setting everything else to metric 5. Your IGP can be IGRP, Open Shortest Path First (OSPF) protocol, RIP, Enhanced Interior Gateway Routing Protocol (EIGRP), or another protocol. Specific keywords such as internal, external, and nssa-external are necessary to redistribute respective routes.
Yes, but iBGP offers more flexibility and more efficient ways to exchange information within an AS. Normally eBGP is the preference, but because of the network backdoor command, EIGRP is the preference.
Your router waits indefinitely for an IGP update about a certain route before the router sends the route to external peers.

Local preference helps you determine which way to exit AS256 in order to reach that network.
The attribute provides a dynamic way to influence another AS in the way to reach a certain route when there are multiple entry points into that AS.
When an update enters the AS with a certain metric, that metric is used to make decisions inside the AS. An issue of the bgp deterministic-med command ensures the comparison of the MED variable at route choice when different peers advertise in the same AS. Therefore, RTA can only compare the metric that comes from RTC to the metric that comes from RTD. Even if you set the community attribute, this attribute does not transmit to neighbors by default.
In order to configure and display in AA:NN, issue the ip bgp-community new-format global configuration command. To block the updates, define an access list on RTC that prevents the transmit to AS100 of any updates that have originated from AS200. So .* represents any path information, which is necessary to permit the transmission of all other updates. In the case of BGP, you specify a string that consists of path information that an input must match. The section Community Attribute discusses community, and this section provides a few examples of how to use community. Please refer to Beau Williamson's book titled Developing IP Multicast Networks, Volume 1 (Cisco Press, 1999) if you need more information about any of the topics presented in this overview. Even low-bandwidth applications can benefit from using Cisco IP multicast when there are thousands of receivers. This group has no physical or geographical boundariesa€”the hosts can be located anywhere on the Internet or any private internetwork.
Packets with link local destination addresses are typically sent with a time-to-live (TTL) value of 1 and are not forwarded by a router. Companies, universities, or other organizations can use limited scope addresses to have local multicast applications that will not be forwarded outside their domain.
Some means had to be devised so that multiple hosts could receive the same packet and still be able to differentiate between several multicast groups. Under IGMP, routers listen to IGMP messages and periodically send out queries to discover which groups are active or inactive on a particular subnet. The router periodically sends out an IGMP membership query to verify that at least one host on the subnet is still interested in receiving traffic directed to that group. RFC 2236, Internet Group Management Protocol, Version 2, describes the specification for IGMPv2.
With this message, the hosts can actively communicate to the local multicast router that they intend to leave the group. This membership information enables Cisco IOS software to forward traffic from only those sources from which receivers requested the traffic. At the time this document was being written, application developers were in the process of porting their applications to the IGMPv3 API. To receive traffic from all sources, which is the behavior of IGMPv2, a host uses EXCLUDE mode membership with an empty EXCLUDE list. RGMP is used on routed segments that contain only routers, such as in a collapsed backbone. The result is that, with CGMP, IP multicast traffic is delivered only to those Catalyst switch ports that are attached to interested receivers. The Layer 2 switches were designed so that several destination MAC addresses could be assigned to a single physical port. When the switch hears the IGMP host report from a host for a particular multicast group, the switch adds the port number of the host to the associated multicast table entry. IGMP Snooping implemented on a low-end switch with a slow CPU could have a severe performance impact when data is sent at high rates. Routers instead generate Protocol Independent Multicast (PIM) messages to join and prune multicast traffic flows at a Layer 3 level.
A multicast router indicates that it is interested in receiving a data flow by sending an RGMP join message for a particular group (part A in Figure 10 ). If one receiver on that branch becomes active and requests the multicast traffic, the router will dynamically modify the distribution tree and start forwarding traffic again. However, this optimization comes at a cost: The routers must maintain path information for each source. The disadvantage of shared trees is that under certain circumstances the paths between the source and receivers might not be the optimal paths, which might introduce some latency in packet delivery.
The router scans through its routing table for the destination address and then forwards a single copy of the unicast packet out the correct interface in the direction of the destination.
If there are multiple downstream paths, the router replicates the packet and forwards it down the appropriate downstream paths (best unicast route metric)a€”which is not necessarily all paths. Although PIM is called a multicast routing protocol, it actually uses the unicast routing table to perform the RPF check function instead of building up a completely independent multicast routing table. This method would be efficient in certain deployments in which there are active receivers on every subnet in the network. PIM-DM supports only source treesa€”that is, (S, G) entriesa€”and cannot be used to build a shared distribution tree.
Network administrators can force traffic to stay on the shared tree by using the Cisco IOS ip pim spt-threshold infinity command. Source data cannot flow up the shared tree toward the RPa€”this would be considered a bidirectional shared tree. This IP address need not be a router address, but can be any unassigned IP address on a network that is reachable throughout the PIM domain. These modifications are necessary and sufficient to allow forwarding of traffic in all routers solely based on the (*, G) multicast routing entries. The network elements (such as routers) assist in suppressing an implosion of NAKs (when a data packet is dropped) and in efficient forwarding of the re-sent data only to the networks that need it. Therefore, any network utilizing internal BGP (iBGP) or external BGP (eBGP) can use MBGP to apply the multiple policy control knobs familiar in BGP to specify the routing policy (and thereby the forwarding policy) for multicast.
The routes associated with multicast routing are used for RPF checking at the interdomain borders. Separate BGP routing tables are maintained for the Unicast Routing Information Base (U-RIB) and the Multicast Routing Information Base (M-RIB).
Network administrators may want to configure several RPs and create several PIM-SM domains. MSDP allows each ISP to have its own local RP and still forward and receive multicast traffic to the Internet. When RPs in remote domains hear about the active sources, they can pass on that information to their local receivers and multicast data can then be forwarded between the domains. MSDP uses a modified RPF check in determining which peers should be forwarded the SA messages. The second thing is to remember that when we are providing for a certain number of hosts, we must subtract two from the mathematical result because we can’t assign the network ID nor the local broadcast address to a host machine. If we apply the formula above, we can answer the question of how many hosts there are per subnet. Then the rest of the available host bits are changed to network bits and then solve as usual. If you go to a wedding reception and are given a piece of the wedding cake, you realize immediately that you do not possess the entire cake.
At first glance, we may think that there are only three networks, the 100 users network, the 50 users network, and the 25 users network. In this event, the interesting octet is the one where the string of ones ends, which is also the octet before the 0 value. If you reside in an EU member state besides UK, import VAT on this purchase is not recoverable. As of March 2013, two of the registries had exhausted their address space, and the others are not far behind.
Although Cisco IT will continue to use NAT and firewalls for network edge security, not having to use it for communications protocols simplifies configuration.
In the early stages of the transition, Cisco IT also used Cisco Primea„? Network Registrar to enable DHCPv6, which provides dynamic IPv6 address assignment.
As part of the Network Optimization Service, Cisco Services uses Cisco Network Collector to retrieve hardware and software configurations from every device in the network.
Upgrading through the Fleet Management Program spread out the capital expense associated with IPv6 adoption. To accomplish this, the team first built a non-production IPv6 network with dual-stack web servers. To complete the project in time for the event, the team decided to use a reverse-proxy design, also known as Server Load Balanced IPv6-to-IPv4 (SLB64). The other rationale was to avoid the need to extend IPv6 connectivity all the way to the web servers, eliminating concerns about whether the web server OS and business applications supported IPv6. The other action was configuring management software, Including Cisco Network Registrar, to monitor the IPv6 Internet presence and automatically assign addresses to IPv6-capable desktops. As Cisco IT began adding dual-stack support across the end-to-end infrastructure, the team had to prepare to support IPv6 with the same SLAs offered for IPv4.
Cisco IT offers formal operational support for IPv6-enabled labs, as well as a formal process to request IPv6 connectivity using existing support tools. When a contact is received (inbound) or initiated (outbound), the Unified CCX checks to see if an existing session already exists with that contact's Implementation ID. Channels are allocated and associated with contacts as needed and are used to support performing actions on contacts.
If the Unified CCX script answers the call and the trigger has been assigned a Dialog Group, Unified CCX establishes a media connection with the caller.
For both products to work together correctly, you should therefore understand how calls are set up when you configure the Unified CM devices. When the Redirect is performed, if the Unified CM destination is available, the call is immediately sent to the Unified CM and released from the CTI Port. In the case of the Unified CCX servers CTI Ports, if the connection to calling or called device cannot be made at the Unified CCX servers installed bandwidth, then a Transcoder channel must be available.
This means that the Unified CM region configuration must allow for connections between devices and the Unified CCX server CTI Ports with the appropriate Codec.
Instead, Unified ICME controls the call treatment by issuing RUN_VRU_SCRIPT commands to Unified IP IVR system. In this type of call flow, the call is under Unified CCE script control when arriving at Unified CCX.
When an agent becomes available, the Unified ICME system sends a Cancel request and the Unified IP IVR system stops running the current script.
The Unified ICME system sends along with the call additional information associated with the call, including a reserved DNIS value, a trunk group, a label for the PG, and instructions for further processing.
Since these variables are used globally throughout the system, they are considered to be premium and should only be used when necessary.
The benefit is that only one VRU Script needs to be defined in the Unified CCX system, and you do not have to use any other variables as parameters to determine which branch to take in the script. Use the Cisco Unified Contact Center Express Solutions Servicing and Troubleshooting Guide for instructions on how to interpret the messages and how to use Trace. However, you can refer to this script in a Run External Script node in Unified ICME by whatever name you want. IN NO EVENT SHALL CISCO OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT, SPECIAL, CONSEQUENTIAL, OR INCIDENTAL DAMAGES, INCLUDING, WITHOUT LIMITATION, LOST PROFITS OR LOSS OR DAMAGE TO DATA ARISING OUT OF THE USE OR INABILITY TO USE THE DESIGNS, EVEN IF CISCO OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. THE DESIGNS DO NOT CONSTITUTE THE TECHNICAL OR OTHER PROFESSIONAL ADVICE OF CISCO, ITS SUPPLIERS OR PARTNERS. The combination of ID and Cisco UCS provides industry-leading platform for Hadoop based applications. Cisco UCS Manager enables rapid and consistent server configuration using service profiles and automation of the ongoing system maintenance activities such as firmware updates across the entire cluster as a single operation. Cisco UCS Manager can be accessed through an intuitive graphical user interface (GUI), a command-line interface (CLI), or an XML application-programming interface (API). Proven in production at some of the most demanding enterprise deployments in the world, the Intel Distribution of Hadoop is supported by experts at Intel with deep optimization experience in the Apache Hadoop software stack as well knowledge of the underlying processor, storage, and networking components. The Intel Distribution for Apache Hadoop software running on Intel Xeon processors helps to eliminate much of the latency and greatly reduce the load on the processors.
The purpose of Kerberos is to enable applications that communicate over a non-secure network to prove their identity to one another in a secure manner.
Instead, the primary component of the user's Kerberos principal is the username that is authenticated. Intel Distribution for Apache Hadoop software has implemented a role based authorization tool that uses the LDAP based group mapping functionality.
If a user is placed in multiple LDAP groups and each LDAP group is assigned a role, then the user gains the permissions of each role assigned to each group. The Intel Manager provides the option to select Hive optionally, during installation and prompts the user to choose the nodes that will run the meta-store and Hive engine components. The Intel Manager optionally, allows the administrator during installation to select and install Pig. The expansion racks also consists of two Cisco Nexus 2232PP Fabric Extenders and sixteen Cisco UCS C240M3 Servers are connected to each of the vertical PDUs for redundancy; thereby, ensuring availability during power source failure, similar to master rack. Any state other than Established is an indication that the two routers did not become neighbors and that the routers cannot exchange BGP updates. The router must use this address rather than the IP address of the interface from which the packet goes.
Also, the eBGP peers have direct connection, but the iBGP peers do not have direct connection. With the introduction of loopback interfaces, the next hop for eBGP is the loopback interface. This redistribution can seem scary because now you dump all your internal routes into BGP; some of these routes can have been learned via BGP and you do not need to send them out again.
The difference is that routes that generate from the network command, redistribution, or static indicate your AS as the origin of these networks. For example, iBGP provides ways to control the best exit point out of the AS with use of local preference.
The disablement of this feature can allow you to carry fewer routes in your IGP and allow BGP to converge more quickly. An issue of the bgp always-compare-med command ensures the comparison of the MED for paths from neighbors in different ASs. The first part of AA:NN represents the AS number, and the second part represents a 2-byte number.
The choice of one method over another method depends on the specific network configuration. First, general topics such as multicast group concept, IP multicast addresses, and Layer 2 multicast addresses are discussed.
High-bandwidth applications, such as MPEG video, may require a large portion of the available network bandwidth for a single stream.
The routers use Protocol Independent Multicast (PIM) to dynamically create a multicast distribution tree. Routers typically are configured with filters to prevent multicast traffic in this address range from flowing outside of an autonomous system (AS) or any user-defined domain. When there is no reply to three consecutive IGMP membership queries, the router times out the group and stops forwarding traffic directed toward that group.
The router then sends out a group-specific query and determines if any remaining hosts are interested in receiving the traffic.
All other ports that have not explicitly requested the traffic will not receive it unless these ports are connected to a multicast router. The router (which must have CGMP enabled on this interface) receives the IGMP report and processes it as it normally would, but also creates a CGMP join message and sends it to the switch (part B in Figure 9).
This allows switches to be connected in a hierarchy and also allows many multicast destination addresses to be forwarded out a single port. When the switch hears the IGMP leave group message from a host, the switch removes the table entry of the host. The solution is to implement IGMP Snooping on high-end switches with special application-specific integrated circuits (ASICs) that can perform the IGMP checks in hardware.
The switch then adds the appropriate port to its forwarding table for that multicast groupa€”similar to the way it handles a CGMP join message.
The traffic is then forwarded down the shared tree from the RP to reach all of the receivers (unless the receiver is located between the source and the RP, in which case it will be serviced directly). In a network that has thousands of sources and thousands of groups, this overhead can quickly become a resource issue on the routers. For example, in Figure 12, the shortest path between Host A (source 1) and Host B (a receiver) would be Router A and Router C.
Forwarding multicast traffic away from the source, rather than to the receiver, is called Reverse Path Forwarding (RPF).
Unlike other routing protocols, PIM does not send and receive routing updates between routers.
Each router along the reverse path compares the unicast routing metric of the RP address to the metric of the source address.
This feature eliminates any source-specific state and allows scaling capability to an arbitrary number of sources. A useful feature of MSDP is that it allows each domain to maintain an independent RP that does not rely on other domains. IP routing automatically selects the topologically closest RP for each source and receiver. If you ask for four plates and a larger piece, then you can go back to your family, cut a piece for your spouse, and smaller pieces for your kids.
Following the same strategy tells us we need six host bits to have 50 users per subnet, because it took six fingers, or six doublings, to get a number bigger than 50. Let’s use that information to our advantage and work backward from there to establish our point-to-point networks. I have a couple of recommendations for websites that will allow you to do subnetting problem after subnetting problem. Using this information, Cisco Services created an easy-to-read IPv6 readiness report that made it easy to see which hardware and software needed upgrades or replacements. Then they replicated static public content from the production web servers to the non-production dual-stack web servers, which exposed the content to users connecting from IPv6-enabled hosts (Figure 6). The DNS server advertises an AAAA record for the website, and the record points to the virtual IPv6 address hosted on the Cisco ACE30 module.
Alerts about availability issues indicate whether the device or application is IPv4 or IPv6. During the transition, Cisco IT worked closely with Cisco engineering teams and Cisco Services to fine-tune the Cisco IOS Software.
The application task in turn invokes an instance of a script associated with the application. Different types of channels are allocated based on the type of contact and the type of dialogue that needs to be supported between the Unified CCX and the Contact. The ICM script will not start until Unified CCX requests instructions from Unified CCE after the Unified CCX Initial Script ends (if one is configured). Examples of this call flow are when you have to queue a caller or if you use the Unified IP IVR for menu based (CED) routing. The agent assigned by the software to handle a call can be defined in either the Unified CM database or the Unified ICME database. The Unified ICME system then sends a Connect command with a Normal label that indicates the extension of the free agent.
Expanded Call Variables are configured both in the Unified ICME system and in the Unified CCX system. For example, if your Translation Route DNIS pool has DNISa€™ 5000, 5001, 5002, and 5003 in it, then you must create four Route Points, each with one of those numbers as the DN of the Route Point. The VRU Script List configuration in Unified CCX Application Administration application is where you couple the ICM External Script name with the Unified CCX script name. With complete, easy-to-order packages that include computing, storage, connectivity, and unified management features, Cisco UCS CPA v2 for Big Data helps enable rapid deployment, delivers predictable performance, and reduces total cost of ownership (TCO). Cisco UCS Manager also offers advanced monitoring with options to raise alarms and send notifications about the health of the entire cluster. Cisco UCS Manager uses service profiles to define the personality, configuration, and connectivity of all resources within Cisco UCS, radically simplifying provisioning of resources so that the process takes minutes instead of days. An ACL is a list of users and groups permitted to take a particular action for an Apache Hadoop service.
Consequently, you can easily increase or decrease a user's access to Apache Hadoop services by adding or remove the user from LDAP groups.
The Intel distribution of Hadoop includes enhancements to run Hive queries on data in Hbase and as a result, can run queries faster by a few orders of magnitude when compared to queries that are run on data in HDFS.
The graph also shows where to apply routing policies in order to enforce some restrictions on the routing behavior. You should also configure an IGP or static routing to allow the neighbors without connection to reach each other.
You use static routes, or an IGP, to introduce two equal-cost paths to reach the destination. The command uses a mask portion because BGP version 4 (BGP4) can handle subnetting and supernetting. Apply careful filtering to make sure that you send to the Internet-only routes that you want to advertise and not to all the routes that you have. Therefore, make an iBGP peering between RTB and RTD in order to not break the flow of the updates. All traffic in AS256 that has that network as a destination transmits with RTD as an exit point. For this reason, you can use route maps to specify the specific updates that need to be tagged with a specific local preference. The bgp always-compare-med command is useful when multiple service providers or enterprises agree on a uniform policy for how to set MED. When RTA gets an update from RTB with metric 50, RTA cannot compare the metric to 120 because RTC and RTB are in different ASs. The access list prevents the transmission of these updates to RTA, which is not the requirement. Then intradomain multicast protocols are reviewed, such as Internet Group Management Protocol (IGMP), Cisco Group Management Protocol (CGMP), Protocol Independent Multicast (PIM) and Pragmatic General Multicast (PGM).
In these applications, IP multicast is the only way to send to more than one receiver simultaneously. The video data stream will then be delivered only to the network segments that are in the path between the source and the receivers. Within an autonomous system or domain, the limited scope address range can be further subdivided so that local multicast boundaries can be defined. IP multicast data flows will be forwarded only to the interested router ports (part B in Figure 10 ). Memory consumption from the size of the multicast routing table is a factor that network designers must take into consideration. Because we are using Router D as the root for a shared tree, the traffic must traverse Routers A, B, D and then C.
RPF makes use of the existing unicast routing table to determine the upstream and downstream neighbors.
If the metric for the source address is better, it will forward a PIM (S, G) join message towards the source. MSDP gives the network administrators the option of selectively forwarding multicast traffic between domains or blocking particular groups or sources. The SA is forwarded by each receiving peer, also using the same modified RPF check, until the SA reaches every MSDP router in the internetworka€”theoretically, the entire multicast Internet.
Because some sources use only one RP and some receivers a different RP, MSDP enables RPs to exchange information about active sources. Previously we had been immediately borrowing the number of folds, or bits, as soon as we knew how many there were.
A mask of 224 gives us an increment of 32 and it is still the fourth octet which is interesting. Since we have already determined that the maximum number of hosts in our three router to router networks is two, let’s count fingers to see how many host bits we need (keeping in mind that we must subtract two from the result). A good goal is to be able to solve any of the problems on these websites in a minute and a half or less. The solution is based on the Cisco ACE 30 Application Control Engine Module for Cisco Catalyst Switches (Figure 7). Recommendations from Cisco IT have been implemented in Cisco network devices for the benefit of customers.
If a session already exists for the contact, the Unified CCX associates it with that session. For example, a CM Telephony call that is presented to Unified CCX will be connected to a CTI Port. An example would be when a caller is prompted by Unified CCX for some information that is intended for subsequent delivery to a Unified CCE Agent. The Unified CCX system then checks the VRU Script Name variable to determine if it needs to run a PreConnect script. In the Unified CCX system, they are configured from the Unified CCX ICM subsystem configuration web page. This simplification allows IT departments to shift their focus from constant maintenance to strategic business initiatives.
The version number changes whenever BGP updates the table with routing information changes. RTC uses this address because the network between RTA, RTC, and RTD is a multiaccess network.
Refer to How the bgp deterministic-med Command Differs from the bgp always-compare-med Command to understand how these commands influence BGP path selection.
Finally, interdomain protocols are covered, such as Multiprotocol Border Gateway Protocol (MBGP), Multicast Source Directory Protocol (MSDP), and Source Specific Multicast (SSM). Figure 1 shows how IP multicast is used to deliver data from one source to many interested recipients. This subdivision is called address scoping and allows for address reuse between these smaller domains. The addition of the leave group message in IGMP Version 2 greatly reduces the leave latency compared to IGMP Version 1.
Multicast routers must listen to all multicast traffic for every group because the IGMP control messages also are sent as multicast traffic. When the router no longer is interested in that data flow, it sends an RGMP leave message and the switch removes the forwarding entry.
Network designers must carefully consider the placement of the rendezvous point (RP) when implementing a shared tree-only environment. If the metric for the RP is the same or better, then the PIM (S, G) join message will be sent in the same direction as the RP. If the receiving MSDP peer is an RP, and the RP has a (*, G) entry for the group in the SA (that is, there is an interested receiver), the RP creates (S, G) state for the source and joins to the shortest path tree for the source.
Once we have made it this far, the rest of the problem is the same as before; that is, list the network IDs, valid host IP address ranges, and local broadcast addresses.
The proxy remains in this middleman role for all traffic between IPv6-enabled endpoints and the production IPv4 web servers.
Intel AES-NI provides seven instructions that help to accelerate the most complex and compute-intensive steps of the AES algorithms.
Paths that the router originates have a weight of 32,768 by default, and other paths have a weight of 0.
With CGMP, the switch must listen only to CGMP join and CGMP leave messages from the router. There is no need to cut it evenly, especially if you want to make sure your piece is larger than your spouse’s piece. If we look at the given information, we immediately see that we have a Class B network with a non-default subnet mask. So we are wasting 410 addresses (510 – 100) in our biggest network and even more in the networks with fewer users. After the contact ends, the session remains idle in memory for a default period of 30 minutes before being automatically deleted. If the Trigger is associated to a Primary and or Secondary Dialogue Group, depending on the type, a Media Channel or an MRCP channel will be allocated. The rest of the multicast traffic is forwarded using the CAM table with the new entries created by CGMP. When the packet is received by the last hop router of the receiver, the last hop router also may join the shortest path tree to the source.
This means that somebody has touched our cake already, which means we don’t have the whole Class B network, we just have OUR piece of it. If an application is triggered by an HTTP Trigger, an HTTP Control Channel will be allocated. The MSDP speaker periodically sends SAs that include all sources within the own domain of the RP.
The actual number of networks is not important, just that we ensure that there are at least twenty hosts in each of the newly created subnets. There will never be more than two hosts on these networks, which means 508 IP addresses will be wasted for each of these in our scenario. Figure 17 shows how data would flow between a source in domain A to a receiver in domain E.
Since we are dealing with a Class B network, that means that the first sixteen bits already belonged to the network before it was touched.
If we list a few of these networks, we should be able to see if we have solved this problem efficiently. The quick way is to look at the octet whose subnet mask value is neither 255 nor 0.A The foolproof way is to see in which octet the string of ones ends.

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