Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.1.x
Implementing EIGRP
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Contents

Implementing EIGRP

The Enhanced Interior Gateway Routing Protocol (EIGRP) is an enhanced version of IGRP developed by Cisco. This module describes the concepts and tasks you need to implement basic EIGRP configuration using Cisco IOS XR software. EIGRP uses distance vector routing technology, which specifies that a router need not know all the router and link relationships for the entire network. Each router advertises destinations with a corresponding distance and upon receiving routes, adjusts the distance and propagates the information to neighboring routes.

For EIGRP configuration information related to the following features, see the Related Documents section of this module.

  • Multiprotocol Label Switching (MPLS) Layer 3 Virtual Private Network (VPN)
  • Site of Origin (SoO) Support

Note


For more information about EIGRP on the Cisco IOS XR software and complete descriptions of the EIGRP commands listed in this module, see the EIGRP Commands chapter in the Cisco ASR 9000 Series Aggregation Services Router Routing Command Reference. To locate documentation for other commands that might appear while executing a configuration task, search online in the Cisco IOS XR software master command index.


Feature History for Implementing EIGRP

Release

Modification

Release 3.7.2

This feature was introduced.

Release 4.3.0

Wide Metric Support feature was added

Prerequisites for Implementing EIGRP

You must be in a user group associated with a task group that includes the proper task IDs. The command reference guides include the task IDs required for each command. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Restrictions for Implementing EIGRP

The following restrictions are employed when running EIGRP on this version of Cisco IOS XR software:

  • Only one instance of an EIGRP process is supported.
  • Bidirectional Forwarding Detection (BFD) feature and the Simple Network Management Protocol (SNMP) MIB are not supported.
  • Interface static routes are not automatically redistributed into EIGRP, because there are no network commands.
  • Metric configuration (either through the default-metric command or a route policy) is required for redistribution of connected and static routes.
  • Auto summary is disabled by default.
  • Stub leak maps are not supported.

Information About Implementing EIGRP

To implement EIGRP, you need to understand the following concepts:

EIGRP Functional Overview

Enhanced Interior Gateway Routing Protocol (EIGRP) is an interior gateway protocol suited for many different topologies and media. EIGRP scales well and provides extremely quick convergence times with minimal network traffic.

EIGRP has very low usage of network resources during normal operation. Only hello packets are transmitted on a stable network. When a change in topology occurs, only the routing table changes are propagated and not the entire routing table. Propagation reduces the amount of load the routing protocol itself places on the network. EIGRP also provides rapid convergence times for changes in the network topology.

The distance information in EIGRP is represented as a composite of available bandwidth, delay, load utilization, and link reliability with improved convergence properties and operating efficiency. The fine-tuning of link characteristics achieves optimal paths.

The convergence technology that EIGRP uses is based on research conducted at SRI International and employs an algorithm referred to as the Diffusing Update Algorithm (DUAL). This algorithm guarantees loop-free operation at every instant throughout a route computation and allows all devices involved in a topology change to synchronize at the same time. Routers that are not affected by topology changes are not involved in recomputations. The convergence time with DUAL rivals that of any other existing routing protocol.

EIGRP Features

EIGRP offers the following features:

  • Fast convergence—The DUAL algorithm allows routing information to converge as quickly as any currently available routing protocol.
  • Partial updates—EIGRP sends incremental updates when the state of a destination changes, instead of sending the entire contents of the routing table. This feature minimizes the bandwidth required for EIGRP packets.
  • Neighbor discovery mechanism—This is a simple hello mechanism used to learn about neighboring routers. It is protocol independent.
  • Variable-length subnet masks (VLSMs).
  • Arbitrary route summarization.
  • Scaling—EIGRP scales to large networks.

The following key features are supported in the Cisco IOS XR implementation:

  • Provider Edge (PE)-Customer Edge (CE) protocol support with Site of Origin (SoO) and Border Gateway Protocol (BGP) cost community support.
  • PECE protocol support for MPLS.

EIGRP Components

EIGRP has the following four basic components:

  • Neighbor discovery or neighbor recovery
  • Reliable transport protocol
  • DUAL finite state machine
  • Protocol-dependent modules

Neighbor discovery or neighbor recovery is the process that routers use to dynamically learn of other routers on their directly attached networks. Routers must also discover when their neighbors become unreachable or inoperative. Neighbor discovery or neighbor recovery is achieved with low overhead by periodically sending small hello packets. As long as hello packets are received, the Cisco IOS XR software can determine that a neighbor is alive and functioning. After this status is determined, the neighboring routers can exchange routing information.

The reliable transport protocol is responsible for guaranteed, ordered delivery of EIGRP packets to all neighbors. It supports intermixed transmission of multicast and unicast packets. Some EIGRP packets must be sent reliably and others need not be. For efficiency, reliability is provided only when necessary. For example, on a multiaccess network that has multicast capabilities (such as Ethernet) it is not necessary to send hello packets reliably to all neighbors individually. Therefore, EIGRP sends a single multicast hello with an indication in the packet informing the receivers that the packet need not be acknowledged. Other types of packets (such as updates) require acknowledgment, which is indicated in the packet. The reliable transport has a provision to send multicast packets quickly when unacknowledged packets are pending. This provision helps to ensure that convergence time remains low in the presence of various speed links.

The DUAL finite state machine embodies the decision process for all route computations. It tracks all routes advertised by all neighbors. DUAL uses the distance information (known as a metric) to select efficient, loop-free paths. DUAL selects routes to be inserted into a routing table based on a calculation of the feasibility condition. A successor is a neighboring router used for packet forwarding that has a least-cost path to a destination that is guaranteed not to be part of a routing loop. When there are no feasible successors but there are neighbors advertising the destination, a recomputation must occur. This is the process whereby a new successor is determined. The amount of time required to recompute the route affects the convergence time. Recomputation is processor intensive; it is advantageous to avoid unneeded recomputation. When a topology change occurs, DUAL tests for feasible successors. If there are feasible successors, it uses any it finds to avoid unnecessary recomputation.

The protocol-dependent modules are responsible for network layer protocol-specific tasks. An example is the EIGRP module, which is responsible for sending and receiving EIGRP packets that are encapsulated in IP. It is also responsible for parsing EIGRP packets and informing DUAL of the new information received. EIGRP asks DUAL to make routing decisions, but the results are stored in the IP routing table. EIGRP is also responsible for redistributing routes learned by other IP routing protocols.

EIGRP Configuration Grouping

Cisco IOS XR software groups all EIGRP configuration under router EIGRP configuration mode, including interface configuration portions associated with EIGRP. To display EIGRP configuration in its entirety, use the show running-config router eigrp command. The command output displays the running configuration for the configured EIGRP instance, including the interface assignments and interface attributes.

EIGRP Configuration Modes

The following examples show how to enter each of the configuration modes. From a mode, you can enter the ? command to display the commands available in that mode.

Router Configuration Mode

The following example shows how to enter router configuration mode:

RP/0/RSP0/CPU0:router# configuration
RP/0/RSP0/CPU0:router(config)# router eigrp 100
RP/0/RSP0/CPU0:router(config-eigrp)#
  

VRF Configuration Mode

The following example shows how to enter VRF configuration mode:

  RP/0/RSP0/CPU0:router# configuration
  RP/0/RSP0/CPU0:router(config)# router eigrp 100
  RP/0/RSP0/CPU0:router(config-eigrp)# vrf customer1
  RP/0/RSP0/CPU0:router(config-eigrp-vrf)#
  

IPv4 Address Family Configuration Mode

The following example shows how to enter IPv4 address family configuration mode:

  RP/0/RSP0/CPU0:router# configuration
  RP/0/RSP0/CPU0:router(config)# router eigrp 100
  RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
  RP/0/RSP0/CPU0:router(config-eigrp-af)#
  

IPv4 VRF Address Family Configuration Mode

The following example shows how to enter IPv4 VRF address family configuration mode:

  RP/0/RSP0/CPU0:router# configuration
  RP/0/RSP0/CPU0:router(config)# router eigrp 100
  RP/0/RSP0/CPU0:router(config-eigrp)# vrf customer1
  RP/0/RSP0/CPU0:router(config-eigrp-vrf)# address-family ipv4
  RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)#
  

Interface Configuration Mode

The following example shows how to enter interface configuration mode in IPv4 address family configuration mode:

  RP/0/RSP0/CPU0:router# configuration
  RP/0/RSP0/CPU0:router(config)# router eigrp 100
  RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
  RP/0/RSP0/CPU0:router(config-eigrp-af)# interface GigabitEthernet 0/3/0/0
  RP/0/RSP0/CPU0:router(config-eigrp-af-if)#
  
  

EIGRP Interfaces

EIGRP interfaces can be configured as either of the following types:

  • Active—Advertises connected prefixes and forms adjacencies. This is the default type for interfaces.
  • Passive—Advertises connected prefixes but does not form adjacencies. The passive command is used to configure interfaces as passive. Passive interfaces should be used sparingly for important prefixes, such as loopback addresses, that need to be injected into the EIGRP domain. If many connected prefixes need to be advertised, then the redistribution of connected routes with the appropriate policy should be used instead.

Redistribution for an EIGRP Process

Routes from other protocols can be redistributed into EIGRP. A route policy can be configured along with the redistribute command. A metric is required, configured either through the default-metric command or under the route policy configured with the redistribute command to import routes into EIGRP.

A route policy allows the filtering of routes based on attributes such as the destination, origination protocol, route type, route tag, and so on. When redistribution is configured under a VRF, EIGRP retrieves extended communities attached to the route in the routing information base (RIB). The SoO is used to filter out routing loops in the presence of MPSL VPN backdoor links.

Metric Weights for EIGRP Routing

EIGRP uses the minimum bandwidth on the path to a destination network and the total delay to compute routing metrics. You can use the metric weights command to adjust the default behavior of EIGRP routing and metric computations. For example, this adjustment allows you to tune system behavior to allow for satellite transmission. EIGRP metric defaults have been carefully selected to provide optimal performance in most networks.

By default, the EIGRP composite metric is a 32-bit quantity that is a sum of the segment delays and lowest segment bandwidth (scaled and inverted) for a given route. For a network of homogeneous media, this metric reduces to a hop count. For a network of mixed media (FDDI, Ethernet, and serial lines running from 9600 bits per second to T1 rates), the route with the lowest metric reflects the most desirable path to a destination.

Mismatched K Values

Mismatched K values (EIGRP metrics) can prevent neighbor relationships from being established and can negatively impact network convergence. The following example explains this behavior between two EIGRP peers (ROUTER-A and ROUTER-B).

The following error message is displayed in the console of ROUTER-B because the K values are mismatched:

  RP/0/RSP0/CPU0:Mar 13 08:19:55:eigrp[163]:%ROUTING-EIGRP-5-NBRCHANGE:IP-EIGRP(0) 1:Neighbor 11.0.0.20 (GigabitEthernet0/6/0/0) is down: K-value mismatch

Two scenarios occur in which this error message can be displayed:

  • The two routers are connected on the same link and configured to establish a neighbor relationship. However, each router is configured with different K values. The following configuration is applied to ROUTER-A. The K values are changed with the metric weights command. A value of 2 is entered for the k1 argument to adjust the bandwidth calculation. The value of 1 is entered for the k3 argument to adjust the delay calculation.
      hostname ROUTER-A!
      interface GigabitEthernet0/6/0/0
       ipv4 address 10.1.1.1 255.255.255.0 
      
      router eigrp 100 
       metric weights 0 2 0 1 0 0
       interface GigabitEthernet0/6/0/0
    
    The following configuration is applied to ROUTER-B. However, the metric weights command is not applied and the default K values are used. The default K values are 1, 0, 1, 0, and 0.
      hostname ROUTER-B!
      interface GigabitEthernet0/6/0/1
       ipv4 address 10.1.1.2 255.255.255.0
      
      router eigrp 100 
       interface GigabitEthernet0/6/0/1
    
    The bandwidth calculation is set to 2 on ROUTER-A and set to 1 (by default) on ROUTER-B. This configuration prevents these peers from forming a neighbor relationship.
  • The K-value mismatch error message can also be displayed if one of the two peers has transmitted a “goodbye” message and the receiving router does not support this message. In this case, the receiving router interprets this message as a K-value mismatch.

Goodbye Message

The goodbye message is a feature designed to improve EIGRP network convergence. The goodbye message is broadcast when an EIGRP routing process is shut down to inform adjacent peers about the impending topology change. This feature allows supporting EIGRP peers to synchronize and recalculate neighbor relationships more efficiently than would occur if the peers discovered the topology change after the hold timer expired.

The following message is displayed by routers that run a supported release when a goodbye message is received:

RP/0/RSP0/CPU0:Mar 13 09:13:17:eigrp[163]:%ROUTING-EIGRP-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 10.0.0.20 (GigabitEthernet0/6/0/0) is down: Interface Goodbye received

A Cisco router that runs a software release that does not support the goodbye message can misinterpret the message as a K-value mismatch and display the following message:

RP/0/RSP0/CPU0:Mar 13 09:13:17:eigrp[163]:%ROUTING-EIGRP-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 10.0.0.20 (GigabitEthernet0/6/0/0) is down: K-value mismatch

Note


The receipt of a goodbye message by a nonsupporting peer does not disrupt normal network operation. The nonsupporting peer terminates the session when the hold timer expires. The sending and receiving routers reconverge normally after the sender reloads.


Percentage of Link Bandwidth Used for EIGRP Packets

By default, EIGRP packets consume a maximum of 50 percent of the link bandwidth, as configured with the bandwidth interface configuration command. You might want to change that value if a different level of link utilization is required or if the configured bandwidth does not match the actual link bandwidth (it may have been configured to influence route metric calculations).

Floating Summary Routes for an EIGRP Process

You can also use a floating summary route when configuring the summary-address command. The floating summary route is created by applying a default route and administrative distance at the interface level. The following scenario illustrates the behavior of this enhancement.

Figure 1 shows a network with three routers, Router-A, Router-B, and Router-C. Router-A learns a default route from elsewhere in the network and then advertises this route to Router-B. Router-B is configured so that only a default summary route is advertised to Router-C. The default summary route is applied to interface 0/1 on Router-B with the following configuration:

  RP/0/RSP0/CPU0:router(config)# router eigrp 100
  RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
  RP/0/RSP0/CPU0:router(config-eigrp-af)# interface GigabitEthernet 0/3/0/0
  RP/0/RSP0/CPU0:router(config-eigrp-af-if)# summary-address 100.0.0.0 0.0.0.0
  
Figure 1. Floating Summary Route Is Applied to Router-B

The configuration of the default summary route on Router-B sends a 0.0.0.0/0 summary route to Router-C and blocks all other routes, including the 10.1.1.0/24 route, from being advertised to Router-C. However, this configuration also generates a local discard route on Router-B, a route for 0.0.0.0/0 to the null 0 interface with an administrative distance of 5. When this route is created, it overrides the EIGRP learned default route. Router-B is no longer able to reach destinations that it would normally reach through the 0.0.0.0.0/0 route.

This problem is resolved by applying a floating summary route to the interface on Router-B that connects to Router-C. The floating summary route is applied by relating an administrative distance to the default summary route on the interface of Router-B with the following statement:

  RP/0/RSP0/CPU0:router(config-if)# summary-address 100 0.0.0.0 0.0.0.0 250
  
  
      

The administrative distance of 250, applied in the above statement, is now assigned to the discard route generated on Router-B. The 0.0.0.0/0, from Router-A, is learned through EIGRP and installed in the local routing table. Routing to Router-C is restored.

If Router-A loses the connection to Router-B, Router-B continues to advertise a default route to Router-C, which allows traffic to continue to reach destinations attached to Router-B. However, traffic destined for networks to Router-A or behind Router-A is dropped when the traffic reaches Router-B.

Figure 2 shows a network with two connections from the core: Router-A and Router-D. Both routers have floating summary routes configured on the interfaces connected to Router-C. If the connection between Router-E and Router-C fails, the network continues to operate normally. All traffic flows from Router-C through Router-B to the hosts attached to Router-A and Router-D.

Figure 2. Floating Summary Route Applied for Dual-Homed Remotes

However, if the link between Router-D and Router-E fails, the network may dump traffic into a black hole because Router-E continues to advertise the default route (0.0.0.0/0) to Router-C, as long as at least one link (other than the link to Router-C) to Router-E is still active. In this scenario, Router-C still forwards traffic to Router-E, but Router-E drops the traffic creating the black hole. To avoid this problem, you should configure the summary address with an administrative distance on only single-homed remote routers or areas in which only one exit point exists between the segments of the network. If two or more exit points exist (from one segment of the network to another), configuring the floating default route can cause a black hole to form.

Split Horizon for an EIGRP Process

Split horizon controls the sending of EIGRP update and query packets. When split horizon is enabled on an interface, update and query packets are not sent for destinations for which this interface is the next hop. Controlling update and query packets in this manner reduces the possibility of routing loops.

By default, split horizon is enabled on all interfaces.

Split horizon blocks route information from being advertised by a router on any interface from which that information originated. This behavior usually optimizes communications among multiple routing devices, particularly when links are broken. However, with nonbroadcast networks (such as Frame Relay and SMDS), situations can arise for which this behavior is less than ideal. For these situations, including networks in which you have EIGRP configured, you may want to disable split horizon.

Adjustment of Hello Interval and Hold Time for an EIGRP Process

You can adjust the interval between hello packets and the hold time.

Routing devices periodically send hello packets to each other to dynamically learn of other routers on their directly attached networks. This information is used to discover neighbors and learn when neighbors become unreachable or inoperative. By default, hello packets are sent every 5 seconds.

You can configure the hold time on a specified interface for a particular EIGRP routing process designated by the autonomous system number. The hold time is advertised in hello packets and indicates to neighbors the length of time they should consider the sender valid. The default hold time is three times the hello interval, or 15 seconds.

Stub Routing for an EIGRP Process

The EIGRP Stub Routing feature improves network stability, reduces resource usage, and simplifies stub router configuration.

Stub routing is commonly used in a hub-and-spoke network topology. In a hub-and-spoke network, one or more end (stub) networks are connected to a remote router (the spoke) that is connected to one or more distribution routers (the hub). The remote router is adjacent only to one or more distribution routers. The only route for IP traffic to follow into the remote router is through a distribution router. This type of configuration is commonly used in WAN topologies in which the distribution router is directly connected to a WAN. The distribution router can be connected to many more remote routers. Often, the distribution router is connected to 100 or more remote routers. In a hub-and-spoke topology, the remote router must forward all nonlocal traffic to a distribution router, so it becomes unnecessary for the remote router to hold a complete routing table. Generally, the distribution router need not send anything more than a default route to the remote router.

When using the EIGRP Stub Routing feature, you need to configure the distribution and remote routers to use EIGRP and configure only the remote router as a stub. Only specified routes are propagated from the remote (stub) router. The stub router responds to all queries for summaries, connected routes, redistributed static routes, external routes, and internal routes with the message “inaccessible.” A router that is configured as a stub sends a special peer information packet to all neighboring routers to report its status as a stub router.

Any neighbor that receives a packet informing it of the stub status does not query the stub router for any routes, and a router that has a stub peer does not query that peer. The stub router depends on the distribution router to send the proper updates to all peers.

Figure 3. Simple Hub-and-Spoke Network.

This figure shows a simple hub-and-spoke configuration.



The stub routing feature by itself does not prevent routes from being advertised to the remote router. In the example in Figure 1 , the remote router can access the corporate network and the Internet through the distribution router only. Having a full route table on the remote router, in this example, would serve no functional purpose because the path to the corporate network and the Internet would always be through the distribution router. The larger route table would only reduce the amount of memory required by the remote router. Bandwidth and memory can be conserved by summarizing and filtering routes in the distribution router. The remote router need not receive routes that have been learned from other networks because the remote router must send all nonlocal traffic, regardless of destination, to the distribution router. If a true stub network is desired, the distribution router should be configured to send only a default route to the remote router. The EIGRP Stub Routing feature does not automatically enable summarization on the distribution router. In most cases, the network administrator needs to configure summarization on the distribution routers.

Without the stub feature, even after the routes that are sent from the distribution router to the remote router have been filtered or summarized, a problem might occur. If a route is lost somewhere in the corporate network, EIGRP could send a query to the distribution router, which in turn sends a query to the remote router even if routes are being summarized. If there is a problem communicating over the WAN link between the distribution router and the remote router, an EIGRP stuck in active (SIA) condition could occur and cause instability elsewhere in the network. The EIGRP Stub Routing feature allows a network administrator to prevent queries from being sent to the remote router.

Route Policy Options for an EIGRP Process

Route policies comprise series of statements and expressions that are bracketed with the route-policy and end-policy keywords. Rather than a collection of individual commands (one for each line), the statements within a route policy have context relative to each other. Thus, instead of each line being an individual command, each policy or set is an independent configuration object that can be used, entered, and manipulated as a unit.

Each line of a policy configuration is a logical subunit. At least one new line must follow the then , else , and end-policy keywords. A new line must also follow the closing parenthesis of a parameter list and the name string in a reference to an AS path set, community set, extended community set, or prefix set (in the EIGRP context). At least one new line must precede the definition of a route policy or prefix set. A new line must appear at the end of a logical unit of policy expression and may not appear anywhere else.

This is the command to set the EIGRP metric in a route policy:

RP/0/RSP0/CPU0:router(config-rpl)# set eigrp-metric bandwidth delay reliability loading mtu

This is the command to provide EIGRP offset list functionality in a route policy:

RP/0/RSP0/CPU0:router(config-rpl)# add eigrp-metric bandwidth delay reliability loading mtu  

A route policy can be used in EIGRP only if all the statements are applicable to the particular EIGRP attach point. The following commands accept a route policy:

  • default-information allowed—Match statements are allowed for destination. No set statements are allowed.
  • route-policy—Match statements are allowed for destination, next hop, and tag. Set statements are allowed for eigrp-metric and tag.
  • redistribute—Match statements are allowed for destination, next hop, source-protocol, tag and route-type. Set statements are allowed for eigrp-metric and tag.

The range for setting a tag is 0 to 255 for internal routes and 0 to 4294967295 for external routes.

EIGRP Layer 3 VPN PE-CE Site-of-Origin

The EIGRP MPLS and IP VPN PE-CE Site-of-Origin (SoO) feature introduces the capability to filter Multiprotocol Label Switching (MPLS) and IP Virtual Private Network (VPN) traffic on a per-site basis for EIGRP networks. SoO filtering is configured at the interface level and is used to manage MPLS and IP VPN traffic and to prevent transient routing loops from occurring in complex and mixed network topologies.

Router Interoperation with the Site-of-Origin Extended Community

The configuration of the SoO extended community allows routers that support this feature to identify the site from which each route originated. When this feature is enabled, the EIGRP routing process on the PE or CE router checks each received route for the SoO extended community and filters based on the following conditions:

  • A received route from BGP or a CE router contains a SoO value that matches the SoO value on the receiving interface:
    • If a route is received with an associated SoO value that matches the SoO value that is configured on the receiving interface, the route is filtered out because it was learned from another PE router or from a backdoor link. This behavior is designed to prevent routing loops.
  • A received route from a CE router is configured with a SoO value that does not match:
    • If a route is received with an associated SoO value that does not match the SoO value that is configured on the receiving interface, the route is accepted into the EIGRP topology table so that it can be redistributed into BGP.
    • If the route is already installed in the EIGRP topology table but is associated with a different SoO value, the SoO value from the topology table is used when the route is redistributed into BGP.
  • A received route from a CE router does not contain a SoO value:
    • If a route is received without a SoO value, the route is accepted into the EIGRP topology table, and the SoO value from the interface that is used to reach the next-hop CE router is appended to the route before it is redistributed into BGP.
    When BGP and EIGRP peers that support the SoO extended community receive these routes, they also receive the associated SoO values and pass them to other BGP and EIGRP peers that support the SoO extended community. This filtering is designed to prevent transient routes from being relearned from the originating site, which prevents transient routing loops from occurring. In conjunction with BGP cost community, EIGRP, BGP, and the RIB ensure that paths over the MPLS VPN core are preferred over backdoor links. For MPLS and IP VPN and SoO configuration information, see Implementing MPLS Layer 3 VPNs in the Cisco  ASR 9000 Series Aggregation Services Router MPLS Configuration Guide.

EIGRP v4/v6 Authentication Using Keychain

EIGRP authentication using keychain introduces the capability to authenticate EIGRP protocol packets on a per-interface basis. The EIGRP routing authentication provides a mechanism to authenticate all EIGRP protocol traffic on one or more interfaces, based on Message Digest 5 (MD5) authentication.

The EIGRP routing authentication uses the Cisco IOS XR software security keychain infrastructure to store and retrieve secret keys and to authenticate incoming and outgoing traffic on a per-interface basis.

EIGRP Wide Metric Computation

The Cisco IOS XR Enhanced Interior Gateway Routing Protocol (EIGRP) implementation is enhanced to perform wide metric computation. This enhancement is to support high bandwidth interfaces.

A new EIGRP command is added and existing EIGRP commands are enhanced to support wide metric computation feature.

  • metric rib-scale—This command was introduced.
  • metric—The picoseconds keyword was added.
  • metric weights—Support was added for the k6 constant.
  • show eigrp interfaces—The command output was modified to display relevant wide metric information.
  • show eigrp neighbors —The command output was modified to display relevant wide metric information.
  • show eigrp topology—The command output was modified to display relevant wide metric information.
  • show protocols—The command output was modified to display relevant wide metric information.

EIGRP Multi-Instance

The Enhanced Interior Gateway Routing Protocol (EIGRP) Multi-Instance feature allows multiple process instances to handle different routing instances and service the same VRF. Each process instance handles the routing instances configured under it. The multiple EIGRP process instance implementation allows to configure the EIGRP using a virtual-name in addition to an autonomous-system number.

How to Implement EIGRP

This section contains instructions for the following tasks:


Note


To save configuration changes, you must commit changes when the system prompts you.


Enabling EIGRP Routing

This task enables EIGRP routing and establishes an EIGRP routing process.

Before You Begin

Although you can configure EIGRP before you configure an IP address, no EIGRP routing occurs until at least one IP address is configured.

SUMMARY STEPS

    1.    configure

    2.    router eigrp as-number

    3.    address-family { ipv4 }

    4.    router-id id

    5.    default-metric bandwidth delay reliability loading mtu

    6.    distance internal-distance external-distance

    7.    interface type interface-path-id

    8.    holdtime seconds

    9.    bandwidth-percent percent

    10.    Use the commit or end command.


DETAILED STEPS
      Command or Action Purpose
    Step 1 configure


    Example:
    RP/0/RSP0/CPU0:router# configure
     

    Enters global configuration mode.

     
    Step 2 router eigrp as-number


    Example:
    RP/0/RSP0/CPU0:router(config)# router eigrp 100
     

    Specifies the autonomous system number of the routing process to configure an EIGRP routing process.

     
    Step 3 address-family { ipv4 }


    Example:
    RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
     

    Enters an address family configuration mode.

     
    Step 4 router-id id


    Example:
    RP/0/RSP0/CPU0:router(config-eigrp)# router-id 172.20.1.1
     

    (Optional) Configures a router-id for an EIGRP process.

    Note   

    It is good practice to use the router-id command to explicitly specify a unique 32-bit numeric value for the router ID. This action ensures that EIGRP can function regardless of the interface address configuration.

     
    Step 5 default-metric bandwidth delay reliability loading mtu


    Example:
    RP/0/RSP0/CPU0:router(config-eigrp-af)# default-metric 1000 100 250 100 1500 
     

    (Optional) Sets metrics for an EIGRP process.

     
    Step 6 distance internal-distance external-distance


    Example:
    RP/0/RSP0/CPU0:router(config-eigrp-af)# distance 80 130
     

    (Optional) Allows the use of two administrative distances—internal and external—that could be a better route to a node.

     
    Step 7 interface type interface-path-id


    Example:
    RP/0/RSP0/CPU0:router(config-eigrp-af)# interface GigabitEthernet 0/1/0/0
     

    Defines the interfaces on which the EIGRP routing protocol runs.

     
    Step 8 holdtime seconds


    Example:
    RP/0/RSP0/CPU0:router(config-eigrp-af-if)# holdtime 30
     

    (Optional) Configures the hold time for an interface.

    Note   

    To ensure nonstop forwarding during RP failovers, as the number of neighbors increase, a higher holdtime than the default value is recommended. With 256 neighbors across all VRFs, we recommend 60 seconds.

     
    Step 9 bandwidth-percent percent


    Example:
    RP/0/RSP0/CPU0:router(config-eigrp-af-if)# bandwidth-percent 75
     

    (Optional) Configures the percentage of bandwidth that may be used by EIGRP on an interface.

     
    Step 10 Use the commit or end command.  

    commit—Saves the configuration changes, and remains within the configuration session.

    end—Prompts user to take one of these actions:
    • Yes— Saves configuration changes and exits the configuration session.
    • No—Exits the configuration session without committing the configuration changes.
    • Cancel—Remains in the configuration mode, without committing the configuration changes.
     

    Configuring Route Summarization for an EIGRP Process

    This task configures route summarization for an EIGRP process.

    You can configure a summary aggregate address for a specified interface. If any more specific routes are in the routing table, EIGRP advertises the summary address from the interface with a metric equal to the minimum of all more specific routes.

    Before You Begin

    Note


    You should not use the summary-address summarization command to generate the default route (0.0.0.0) from an interface. This command creates an EIGRP summary default route to the null 0 interface with an administrative distance of 5. The low administrative distance of this default route can cause this route to displace default routes learned from other neighbors from the routing table. If the default route learned from the neighbors is displaced by the summary default route or the summary route is the only default route present, all traffic destined for the default route does not leave the router; instead, this traffic is sent to the null 0 interface, where it is dropped.

    The recommended way to send only the default route from a given interface is to use a route-policy command.


    SUMMARY STEPS

      1.    configure

      2.    router eigrp as-number

      3.    address-family { ipv4 }

      4.    route-policy name out

      5.    interface type interface-path-id

      6.    summary-address ip-address { / length | mask } [ admin-distance ]

      7.    Use the commit or end command.


    DETAILED STEPS
        Command or Action Purpose
      Step 1 configure


      Example:
      RP/0/RSP0/CPU0:router# configure
       

      Enters global configuration mode.

       
      Step 2 router eigrp as-number


      Example:
      RP/0/RSP0/CPU0:router(config)# router eigrp 100
       

      Specifies the AS number of the routing process to configure an EIGRP routing process

       
      Step 3 address-family { ipv4 }


      Example:
      RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
       

      Enters an address family configuration mode.

       
      Step 4 route-policy name out


      Example:
      RP/0/RSP0/CPU0:router(config-eigrp-af)# route-policy FILTER_DEFAULT out
       

      Applies a routing policy to updates advertised to or received from an EIGRP neighbor.

       
      Step 5 interface type interface-path-id


      Example:
      RP/0/RSP0/CPU0:router(config-eigrp-af)# interface GigabitEthernet 0/1/0/0 
       

      Defines the interfaces on which the EIGRP routing protocol runs.

       
      Step 6 summary-address ip-address { / length | mask } [ admin-distance ]


      Example:
      RP/0/RSP0/CPU0:router(config-eigrp-af-if)# summary-address 192.168.0.0/16 95 
       

      Configures a summary aggregate address for the specified EIGRP interface.

       
      Step 7 Use the commit or end command.  

      commit—Saves the configuration changes, and remains within the configuration session.

      end—Prompts user to take one of these actions:
      • Yes— Saves configuration changes and exits the configuration session.
      • No—Exits the configuration session without committing the configuration changes.
      • Cancel—Remains in the configuration mode, without committing the configuration changes.
       

      Redistributing Routes for EIGRP

      This task explains how to redistribute routes, apply limits on the number of routes, and set timers for nonstop forwarding.

      SUMMARY STEPS

        1.    configure

        2.    router eigrp as-number

        3.    address-family { ipv4 }

        4.    redistribute {{ bgp | connected | isis | ospf | rip | static } [ as-number ]} [ route-policy name ]

        5.    redistribute maximum-prefix maximum [ threshold ] [[ dampened ] [ reset-time minutes ] [ restart minutes ] [ restart-count number ] | [ warning-only ]]

        6.    timers nsf route-hold seconds

        7.    maximum paths maximum

        8.    maximum-prefix maximum [ threshold ] [[ dampened ] [ reset-time minutes ] [ restart minutes ] [ restart-count number ] | [ warning-only]]

        9.    Use the commit or end command.


      DETAILED STEPS
          Command or Action Purpose
        Step 1 configure


        Example:
        RP/0/RSP0/CPU0:router# configure
         

        Enters global configuration mode.

         
        Step 2 router eigrp as-number


        Example:
        RP/0/RSP0/CPU0:router(config)# router eigrp 100
         

        Specifies the AS number of the routing process to configure an EIGRP routing process.

         
        Step 3 address-family { ipv4 }


        Example:
        RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
         

        Enters an address family configuration mode.

         
        Step 4 redistribute {{ bgp | connected | isis | ospf | rip | static } [ as-number ]} [ route-policy name ]


        Example:
        RP/0/RSP0/CPU0:router(config-eigrp-af)# redistribute bgp 100
         

        Redistributes the routes from the specified protocol and AS number to the EIGRP process. Optionally, the redistributed routes can be filtered into the EIGRP process by providing the route policy.

         
        Step 5 redistribute maximum-prefix maximum [ threshold ] [[ dampened ] [ reset-time minutes ] [ restart minutes ] [ restart-count number ] | [ warning-only ]]


        Example:
        RP/0/RSP0/CPU0:router(config-eigrp-af)# redistribute maximum-prefix 5000 95 warning-only
         

        Limits the maximum number of prefixes that are redistributed to the EIGRP process.

         
        Step 6 timers nsf route-hold seconds


        Example:
        RP/0/RSP0/CPU0:router(config-eigrp-af)# timers nsf route-hold 120
         

        Sets the timer that determines how long an NSF-aware EIGRP router holds routes for an inactive peer.

         
        Step 7 maximum paths maximum


        Example:
        RP/0/RSP0/CPU0:router(config-eigrp-af)# maximum paths 10
         

        Controls the maximum number of parallel routes that the EIGRP can support.

         
        Step 8 maximum-prefix maximum [ threshold ] [[ dampened ] [ reset-time minutes ] [ restart minutes ] [ restart-count number ] | [ warning-only]]


        Example:
        RP/0/RSP0/CPU0:router(config-eigrp-af)# maximum-prefix 50000
         

        Limits the number of prefixes that are accepted under an address family by EIGRP.

         
        Step 9 Use the commit or end command.  

        commit—Saves the configuration changes, and remains within the configuration session.

        end—Prompts user to take one of these actions:
        • Yes— Saves configuration changes and exits the configuration session.
        • No—Exits the configuration session without committing the configuration changes.
        • Cancel—Remains in the configuration mode, without committing the configuration changes.
         

        Creating a Route Policy and Attaching It to an EIGRP Process

        This task defines a route policy and shows how to attach it to an EIGRP process.

        A route policy definition consists of the route-policy command and name argument followed by a sequence of optional policy statements, and then closed with the end-policy command.

        A route policy is not useful until it is applied to routes of a routing protocol.

        SUMMARY STEPS

          1.    configure

          2.    route-policy name

          3.    set eigrp-metric bandwidth delay reliability load mtu

          4.    end-policy

          5.    Use the commit or end command.

          6.    configure

          7.    router eigrp as-number

          8.    address-family { ipv4 }

          9.    route-policy route-policy-name { in | out }

          10.    Use the commit or end command.


        DETAILED STEPS
            Command or Action Purpose
          Step 1 configure


          Example:
          RP/0/RSP0/CPU0:router# configure
           

          Enters global configuration mode.

           
          Step 2 route-policy name


          Example:
          RP/0/RSP0/CPU0:router(config)# route-policy IN-IPv4
           

          Defines a route policy and enters route-policy configuration mode.

           
          Step 3 set eigrp-metric bandwidth delay reliability load mtu


          Example:
          RP/0/RSP0/CPU0:router(config-rpl)# set eigrp metric 42 100 200 100 1200
           

          (Optional) Sets the EIGRP metric attribute.

           
          Step 4 end-policy


          Example:
          RP/0/RSP0/CPU0:router(config-rpl)# end-policy
           

          Ends the definition of a route policy and exits route-policy configuration mode.

           
          Step 5 Use the commit or end command.  

          commit—Saves the configuration changes, and remains within the configuration session.

          end—Prompts user to take one of these actions:
          • Yes— Saves configuration changes and exits the configuration session.
          • No—Exits the configuration session without committing the configuration changes.
          • Cancel—Remains in the configuration mode, without committing the configuration changes.
           
          Step 6 configure


          Example:
          RP/0/RSP0/CPU0:router# configure
           

          Enters global configuration mode.

           
          Step 7 router eigrp as-number


          Example:
          RP/0/RSP0/CPU0:router(config)# router eigrp 100
           

          Specifies the autonomous system number of the routing process to configure an EIGRP routing process.

           
          Step 8 address-family { ipv4 }


          Example:
          RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
           

          Enters an address family configuration mode.

           
          Step 9 route-policy route-policy-name { in | out }


          Example:
          RP/0/RSP0/CPU0:router(config-eigrp-af)# route-policy IN-IPv4 in
           

          Applies a routing policy to updates advertised to or received from an EIGRP neighbor.

           
          Step 10 Use the commit or end command.  

          commit—Saves the configuration changes, and remains within the configuration session.

          end—Prompts user to take one of these actions:
          • Yes— Saves configuration changes and exits the configuration session.
          • No—Exits the configuration session without committing the configuration changes.
          • Cancel—Remains in the configuration mode, without committing the configuration changes.
           

          Configuring Stub Routing for an EIGRP Process

          This task configures the distribution and remote routers to use an EIGRP process for stub routing.

          Before You Begin

          Note


          EIGRP stub routing should be used only on remote routers. A stub router is defined as a router connected to the network core or distribution layer through which core transit traffic should not flow. A stub router should not have any EIGRP neighbors other than distribution routers. Ignoring this restriction causes undesirable behavior.


          SUMMARY STEPS

            1.    configure

            2.    router eigrp as-number

            3.    address-family { ipv4 }

            4.    stub [ receive-only | {[ connected ] [ redistributed ] [ static ] [ summary ]}]

            5.    Use the commit or end command.

            6.    show eigrp [ ipv4 ] [ vrf { vrf-name | all }] neighbors [ as-number ] [ detail ] [ type interface-path-id | static ]


          DETAILED STEPS
              Command or Action Purpose
            Step 1 configure


            Example:
            RP/0/RSP0/CPU0:router# configure
             

            Enters global configuration mode.

             
            Step 2 router eigrp as-number


            Example:
            RP/0/RSP0/CPU0:router(config)# router eigrp 100
             

            Specifies the autonomous system number of the routing process to configure an EIGRP routing process.

             
            Step 3 address-family { ipv4 }


            Example:
            RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
             

            Enters an address family configuration mode.

             
            Step 4 stub [ receive-only | {[ connected ] [ redistributed ] [ static ] [ summary ]}]


            Example:
            RP/0/RSP0/CPU0:router(config-eigrp-af)# stub receive-only 
             

            Configures a router as a stub for EIGRP.

             
            Step 5 Use the commit or end command.  

            commit—Saves the configuration changes, and remains within the configuration session.

            end—Prompts user to take one of these actions:
            • Yes— Saves configuration changes and exits the configuration session.
            • No—Exits the configuration session without committing the configuration changes.
            • Cancel—Remains in the configuration mode, without committing the configuration changes.
             
            Step 6 show eigrp [ ipv4 ] [ vrf { vrf-name | all }] neighbors [ as-number ] [ detail ] [ type interface-path-id | static ]


            Example:
            RP/0/RSP0/CPU0:router# show eigrp neighbors detail
             

            Verifies that a remote router has been configured as a stub router with EIGRP.

            The last line of the output shows the stub status of the remote or spoke router.

             

            Configuring EIGRP as a PE-CE Protocol

            Perform this task to configure EIGRP on the provider edge (PE) and establish provider edge-to-customer edge (PE-CE) communication using EIGRP.

            SUMMARY STEPS

              1.    configure

              2.    router eigrp as-number

              3.    vrf vrf-name

              4.    address-family { ipv4 }

              5.    router-id router-id

              6.    autonomous-system as-number

              7.    redistribute {{ bgp | connected | isis | ospf | ospfv3 | rip | static } [ as-number | instance-name ]} [ route-policy name ]

              8.    interface type interface-path-id

              9.    site-of-origin { as-number:number | ip-address : number }

              10.    Use the commit or end command.


            DETAILED STEPS
                Command or Action Purpose
              Step 1 configure


              Example:
              RP/0/RSP0/CPU0:router# configure
               

              Enters global configuration mode.

               
              Step 2 router eigrp as-number


              Example:
              RP/0/RSP0/CPU0:router(config)# router eigrp 100
               

              Specifies the autonomous system number of the routing process to configure an EIGRP routing process

               
              Step 3 vrf vrf-name


              Example:
              RP/0/RSP0/CPU0:router(config-eigrp)# vrf vrf_A
               

              Configures a VPN routing and forwarding (VRF) instance.

               
              Step 4 address-family { ipv4 }


              Example:
              RP/0/RSP0/CPU0:router(config-eigrp-vrf)# address-family ipv4
               

              Enters a VRF address family configuration mode.

               
              Step 5 router-id router-id


              Example:
              RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)# router-id 33
               

              Configures a router ID for the EIGRP process.

               
              Step 6 autonomous-system as-number


              Example:
              RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)# autonomous-system 2
               

              Configures an EIGRP routing process to run within the VRF instance.

              Note   

              You must configure the autonomous system under VRF configuration to bring-up the VRF interface.

               
              Step 7 redistribute {{ bgp | connected | isis | ospf | ospfv3 | rip | static } [ as-number | instance-name ]} [ route-policy name ]


              Example:
              RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)# redistribute bgp 100
               

              Injects routes from one routing domain into EIGRP.

               
              Step 8 interface type interface-path-id


              Example:
              RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)# interface gigabitEthernet 0/1/5/0
               

              Configures the interface on which EIGRP the routing protocol runs.

               
              Step 9 site-of-origin { as-number:number | ip-address : number }


              Example:
              RP/0/RSP0/CPU0:router(config-eigrp-vrf-af-if)# site-of-origin 3:4
               

              Configures the site-of-origin (SoO) filtering on the EIGRP interface.

               
              Step 10 Use the commit or end command.  

              commit—Saves the configuration changes, and remains within the configuration session.

              end—Prompts user to take one of these actions:
              • Yes— Saves configuration changes and exits the configuration session.
              • No—Exits the configuration session without committing the configuration changes.
              • Cancel—Remains in the configuration mode, without committing the configuration changes.
               

              Redistributing BGP Routes into EIGRP

              Perform this task to redistribute BGP routes into EIGRP.

              Typically, EIGRP routes are redistributed into BGP with extended community information appended to the route. BGP carries the route over the VPN backbone with the EIGRP-specific information encoded in the BGP extended community attributes. After the peering customer site receives the route, EIGRP redistributes the BGP route then extracts the BGP extended community information and reconstructs the route as it appeared in the original customer site.

              When redistributing BGP routes into EIGRP, the receiving provider edge (PE) EIGRP router looks for BGP extended community information. If the information is received, it is used to recreate the original EIGRP route. If the information is missing, EIGRP uses the configured default metric value.

              If the metric values are not derived from the BGP extended community and a default metric is not configured, the route is not advertised to the customer edge (CE) router by the PE EIGRP. When BGP is redistributed into BGP, metrics may not be added to the BGP prefix as extended communities; for example, if EIGRP is not running on the other router. In this case, EIGRP is redistributed into BGP with a “no-metrics” option.

              SUMMARY STEPS

                1.    configure

                2.    router eigrp as-number

                3.    vrf vrf-name

                4.    address-family { ipv4 }

                5.    redistribute {{ bgp | connected | isis | ospf | ospfv3 | rip | static } [ as-number | instance-name ]} [ route-policy name ]

                6.    route-policy route-policy-name { in | out }

                7.    default-metric bandwidth delay reliability loading mtu

                8.    Use the commit or end command.


              DETAILED STEPS
                  Command or Action Purpose
                Step 1 configure


                Example:
                RP/0/RSP0/CPU0:router# configure
                 

                Enters global configuration mode.

                 
                Step 2 router eigrp as-number


                Example:
                RP/0/RSP0/CPU0:router(config)# router eigrp 100
                 

                Specifies the autonomous system number of the routing process to configure an EIGRP routing process.

                 
                Step 3 vrf vrf-name


                Example:
                RP/0/RSP0/CPU0:router(config-eigrp)# router eigrp 100
                 

                Configures a VRF instance.

                 
                Step 4 address-family { ipv4 }


                Example:
                RP/0/RSP0/CPU0:router(config-eigrp-vrf)# address-family ipv4
                 

                Enters a VRF address family configuration mode.

                 
                Step 5 redistribute {{ bgp | connected | isis | ospf | ospfv3 | rip | static } [ as-number | instance-name ]} [ route-policy name ]


                Example:
                RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)# redistribute bgp 100
                 

                Injects routes from one routing domain into EIGRP.

                 
                Step 6 route-policy route-policy-name { in | out }


                Example:
                RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)# route-policy policy_A in
                 

                Applies a routing policy to updates advertised to or received from an EIGRP neighbor.

                 
                Step 7 default-metric bandwidth delay reliability loading mtu


                Example:
                RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)# default-metric 1000 100 250 100 1500
                 

                Configures metrics for EIGRP.

                 
                Step 8 Use the commit or end command.  

                commit—Saves the configuration changes, and remains within the configuration session.

                end—Prompts user to take one of these actions:
                • Yes— Saves configuration changes and exits the configuration session.
                • No—Exits the configuration session without committing the configuration changes.
                • Cancel—Remains in the configuration mode, without committing the configuration changes.
                 

                Monitoring EIGRP Routing

                The commands in this section are used to log neighbor adjacency changes, monitor the stability of the routing system, and help detect problems.

                SUMMARY STEPS

                  1.    configure

                  2.    router eigrp as-number

                  3.    address-family [ ipv4 ]

                  4.    log-neighbor-changes

                  5.    log-neighbor-warnings

                  6.    Use the commit or end command.

                  7.    clear eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] neighbors [ ip-address | type interface-path-id ]

                  8.    clear eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] topology [ prefix mask ] [ prefix / length ]

                  9.    show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] accounting

                  10.    show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] interfaces [ type interface-path-id ] [ detail ]

                  11.    show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] neighbors [ detail ] [ type interface-path-id | static ]

                  12.    show protocols eigrp [ vrf vrf-name ]

                  13.    show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] topology [ ip-address mask ] [ active | all-links | detail-links | pending | summary | zero-successors ]

                  14.    show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] traffic


                DETAILED STEPS
                    Command or Action Purpose
                  Step 1 configure


                  Example:
                  RP/0/RSP0/CPU0:router# configure
                   

                  Enters global configuration mode.

                   
                  Step 2 router eigrp as-number


                  Example:
                  RP/0/RSP0/CPU0:router(config)# router eigrp 100
                   

                  Specifies the autonomous system number of the routing process to configure an EIGRP routing process.

                   
                  Step 3 address-family [ ipv4 ]


                  Example:
                  RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
                  
                   

                  Enters an address family configuration mode.

                   
                  Step 4 log-neighbor-changes


                  Example:
                  RP/0/RSP0/CPU0:router(config-eigrp-af)# log-neighbor-changes
                   

                  Enables the logging of changes in EIGRP neighbor adjacencies.

                   
                  Step 5 log-neighbor-warnings


                  Example:
                  RP/0/RSP0/CPU0:router(config-eigrp-af)# log-neighbor-warnings
                   

                  Enables the logging of EIGRP neighbor warning messages.

                   
                  Step 6 Use the commit or end command.  

                  commit—Saves the configuration changes, and remains within the configuration session.

                  end—Prompts user to take one of these actions:
                  • Yes— Saves configuration changes and exits the configuration session.
                  • No—Exits the configuration session without committing the configuration changes.
                  • Cancel—Remains in the configuration mode, without committing the configuration changes.
                   
                  Step 7 clear eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] neighbors [ ip-address | type interface-path-id ]


                  Example:
                  RP/0/RSP0/CPU0:routerr# clear eigrp 20 neighbors GigabitEthernet 0/1/0/0
                   

                  Deletes EIGRP and VPN neighbor entries from the appropriate table.

                   
                  Step 8 clear eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] topology [ prefix mask ] [ prefix / length ]


                  Example:
                  RP/0/RSP0/CPU0:router# clear eigrp topology
                   

                  Deletes EIGRP and VRF topology entries from the appropriate tab.

                   
                  Step 9 show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] accounting


                  Example:
                  RP/0/RSP0/CPU0:router# show eigrp vrf all accounting
                   

                  Displays prefix accounting information for EIGRP processes.

                   
                  Step 10 show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] interfaces [ type interface-path-id ] [ detail ]


                  Example:
                  RP/0/RSP0/CPU0:router# show eigrp interfaces detail
                   

                  Displays information about interfaces configured for EIGRP.

                   
                  Step 11 show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] neighbors [ detail ] [ type interface-path-id | static ]


                  Example:
                  RP/0/RSP0/CPU0:router# show eigrp neighbors 20 detail static
                   

                  Displays the neighbors discovered by EIGRP.

                   
                  Step 12 show protocols eigrp [ vrf vrf-name ]


                  Example:
                  RP/0/RSP0/CPU0:router# show protocols eigrp
                   

                  Displays information about the EIGRP process configuration.

                   
                  Step 13 show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] topology [ ip-address mask ] [ active | all-links | detail-links | pending | summary | zero-successors ]


                  Example:
                  RP/0/RSP0/CPU0:router# show eigrp topology 10.0.0.1 253.254.255.255 summary
                   

                  Displays entries in the EIGRP topology table.

                   
                  Step 14 show eigrp [ as-number ] [ vrf { vrf | all }] [ ipv4 ] traffic


                  Example:
                  RP/0/RSP0/CPU0:router# show eigrp traffic
                   

                  Displays the number of EIGRP packets sent and received.

                   

                  Configuring an EIGRP Authentication Keychain

                  Perform the following tasks to configure an authentication keychain on EIGRP interfaces.

                  Configuring an Authentication Keychain for an IPv4/IPv6 Interface on a Default VRF

                  Perform this task to configure an authentication keychain for an IPv4/IPv6 interface on a default VRF.

                  SUMMARY STEPS

                    1.    configure

                    2.    router eigrp as-number

                    3.    address-family { ipv4 | ipv6 }

                    4.    interface type interface-path-id

                    5.    authentication keychain keychain-name

                    6.    Use the commit or end command.


                  DETAILED STEPS
                      Command or Action Purpose
                    Step 1 configure


                    Example:
                    RP/0/RSP0/CPU0:router# configure
                     

                    Enters global configuration mode.

                     
                    Step 2 router eigrp as-number


                    Example:
                    RP/0/RSP0/CPU0:router(config)# router eigrp 100
                     

                    Specifies the autonomous system number of the routing process to configure an EIGRP routing process.

                     
                    Step 3 address-family { ipv4 | ipv6 }


                    Example:
                    RP/0/RSP0/CPU0:router(config-eigrp)# address-family ipv4
                     

                    Enters a VRF address family configuration mode.

                     
                    Step 4 interface type interface-path-id


                    Example:
                    RP/0/RSP0/CPU0:router(config-eigrp-af)#
                      interface gigabitEthernet 0/1/5/0
                      
                     

                    Configures the interface on which EIGRP the routing protocol runs.

                     
                    Step 5 authentication keychain keychain-name


                    Example:
                    RP/0/RSP0/CPU0:router(config-eigrp-af-if)# authentication keychain
                     

                    Authenticates all EIGRP protocol traffic on the interface, based on the MD5 algorithm.

                     
                    Step 6 Use the commit or end command.  

                    commit—Saves the configuration changes, and remains within the configuration session.

                    end—Prompts user to take one of these actions:
                    • Yes— Saves configuration changes and exits the configuration session.
                    • No—Exits the configuration session without committing the configuration changes.
                    • Cancel—Remains in the configuration mode, without committing the configuration changes.
                     

                    Configuring an Authentication Keychain for an IPv4/IPv6 Interface on a Nondefault VRF

                    Perform this task to configure an authentication keychain for an IPv4/IPv6 interface on a nondefault VRF.

                    SUMMARY STEPS

                      1.    configure

                      2.    router eigrp as-number

                      3.    vrf vrf-name

                      4.    address-family { ipv4 | ipv6 }

                      5.    interface type interface-path-id

                      6.    authentication keychain keychain-name

                      7.    Use the commit or end command.


                    DETAILED STEPS
                        Command or Action Purpose
                      Step 1 configure


                      Example:
                      RP/0/RSP0/CPU0:router# configure
                       

                      Enters global configuration mode.

                       
                      Step 2 router eigrp as-number


                      Example:
                      RP/0/RSP0/CPU0:router(config)# router eigrp 100
                       

                      Specifies the autonomous system number of the routing process to configure an EIGRP routing process.

                       
                      Step 3 vrf vrf-name


                      Example:
                      RP/0/RSP0/CPU0:router(config-eigrp)# vrf vrf1
                       

                      Creates a VRF instance and enters VRF configuration mode.

                       
                      Step 4 address-family { ipv4 | ipv6 }


                      Example:
                      RP/0/RSP0/CPU0:router(config-eigrp-vrf)# address-family ipv4
                       

                      Enters a VRF address family configuration mode.

                       
                      Step 5 interface type interface-path-id


                      Example:
                      RP/0/RSP0/CPU0:router(config-eigrp-vrf-af)#
                        interface gigabitEthernet 0/1/5/0
                        
                       

                      Configures the interface on which EIGRP runs.

                       
                      Step 6 authentication keychain keychain-name


                      Example:
                      RP/0/RSP0/CPU0:router(config-eigrp-vrf-af-if)# authentication keychain
                       

                      Authenticates all EIGRP protocol traffic on the interface, based on the MD5 algorithm.

                       
                      Step 7 Use the commit or end command.  

                      commit—Saves the configuration changes, and remains within the configuration session.

                      end—Prompts user to take one of these actions:
                      • Yes— Saves configuration changes and exits the configuration session.
                      • No—Exits the configuration session without committing the configuration changes.
                      • Cancel—Remains in the configuration mode, without committing the configuration changes.
                       

                      Configuration Examples for Implementing EIGRP

                      This section provides the following configuration examples:

                      Configuring a Basic EIGRP Configuration: Example

                      The following example shows how to configure EIGRP with a policy that filters incoming routes. This is a typical configuration for a router that has just one neighbor, but advertises other connected subnets.

                        router eigrp 144
                          address-family ipv4
                            metric maximum-hops 20 
                            router-id 10.10.9.4 
                            route-policy GLOBAL_FILTER_POLICY in
                            log-neighbor-changes 
                            log-neighbor-warnings 
                            interface Loopback0
                            !
                            interface GigabitEthernet 0/2/0/0
                              passive-interface 
                            !
                            interface GigabitEthernet 0/6/0/0
                              hello-interval 8 
                              hold-time 30 
                              summary-address 10.0.0.0 255.255.0.0 
                              !

                      Configuring an EIGRP Stub Operation: Example

                      The following example shows how to configure an EIGRP stub. Stub operation allows only connected, static, and summary routes to be advertised to neighbors.

                        router eigrp 200
                          address-family ipv4
                            stub connected static summary 
                            router-id 172.16.82.22 
                            log-neighbor-changes 
                            log-neighbor-warnings 
                            redistribute connected route-policy CONN_POLICY 
                            interface GigabitEthernet0/6/0/0
                              passive-interface 
                              neighbor 10.0.0.31
                            !
                            interface GigabitEthernet0/6/0/1
                              passive-interface 
                              neighbor 10.0.1.21
                              !
                            !
                          !
                        

                      Configuring an EIGRP PE-CE Configuration with Prefix-Limits: Example

                      The following example shows how to configure EIGRP to operate as a PE-CE protocol on a PE router. The configuration is under VRF CUSTOMER_1. A maximum prefix is typically configured to ensure that one set of customer routes do not overwhelm the EIGRP process.

                        router eigrp 500
                          vrf CUSTOMER_1
                            address-family ipv4
                              timers nsf route-hold 300 
                              router-id 172.16.6.11 
                              maximum-prefix 450 70 
                              default-metric 200000 10000 195 10 1500 
                              log-neighbor-changes 
                              log-neighbor-warnings 
                              redistribute maximum-prefix 350 70 
                              redistribute bgp 1.65500 route-policy SITE_1_POLICY 
                              interface GigabitEthernet 0/4/0/5
                              neighbor 10.22.1.1 
                              !
                            !
                          !
                        

                      Configuring an EIGRP Authentication Keychain: Example

                      The following example shows how to configure an authentication keychain for an IPv4 interface on a nondefault VRF:

                      config
                      router eigrp 100
                      vrf vrf1
                      address-family ipv4 
                      interface POS 0/1/0/0
                      authentication keychain key1
                      
                      

                      The following example shows how to configure an authentication keychain for an IPv6 interface on a default VRF:

                      config
                      router eigrp 100
                      address-family ipv6
                      interface POS 0/1/0/0
                      authentication keychain key2
                      
                      

                      Additional References

                      The following sections provide references related to implementing EIGRP.

                      Related Documents

                      Related Topic

                      Document Title

                      EIGRP commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

                      Cisco ASR 9000 Series Aggregation Services Router Routing Command Reference

                      MPLS VPN support for EIGRP feature information

                      Implementing MPLS Layer 3 VPNs module and Implementing MPLS Layer 2 VPNs module in Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide

                      Site of Origin (SoO) support for EIGRP feature information

                      Implementing MPLS Traffic Engineering on Cisco ASR 9000 Series Router module in Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide

                      MIB Reference

                      Cisco ASR 9000 Series Aggregation Services Router MIB Specification Guide.

                      Standards

                      Standards

                      Title

                      No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

                      MIBs

                      MIBs

                      MIBs Link

                      To locate and download MIBs using Cisco IOS XR software, use the Cisco MIB Locator found at the following URL and choose a platform under the Cisco Access Products menu: http:/​/​cisco.com/​public/​sw-center/​netmgmt/​cmtk/​mibs.shtml

                      RFCs

                      RFCs

                      Title

                      No new or modified RFCs are supported by this feature, and support for existing standards has not been modified by this feature.

                      Technical Assistance

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