Cisco IOS XE IP Routing Protocols Configuration Guide, Release 2
EIGRP Support for Route Map Filtering

Table Of Contents

EIGRP Support for Route Map Filtering

Finding Feature Information

Contents

Information About EIGRP Support for Route Map Filtering

EIGRP Route Map Support

How to Configure EIGRP Support for Route Map Filtering

Configuring EIGRP Metrics Using a Route Map

Verifying EIGRP Metrics

Configuration Examples for EIGRP Support for Route Map Filtering

Configuring EIGRP Metrics Using a Route Map: Examples

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Feature Information for EIGRP Support for Route Map Filtering


EIGRP Support for Route Map Filtering


First Published: May 17, 2004
Last Updated: May 4, 2009

The EIGRP Support for Route Map Filtering feature enables Enhanced Interior Gateway Routing Protocol (EIGRP) to interoperate with other protocols by filtering inbound and outbound traffic based on complex route map options. In addition to the existing route map facility, several extended filtering options are introduced to provide EIGRP-specific match choices.

Finding Feature Information

For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for EIGRP Support for Route Map Filtering" section.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS XE software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

Information About EIGRP Support for Route Map Filtering

How to Configure EIGRP Support for Route Map Filtering

Configuration Examples for EIGRP Support for Route Map Filtering

Additional References

Feature Information for EIGRP Support for Route Map Filtering

Information About EIGRP Support for Route Map Filtering

To implement EIGRP route map filtering, you should understand the following concept:

EIGRP Route Map Support

EIGRP Route Map Support

EIGRP support for route map filtering enables EIGRP to interoperate with other protocols by filtering inbound and outbound traffic based on route map options. Additional EIGRP-specific match choices are introduced to allow flexibility in fine-tuning EIGRP network operations.

EIGRP now supports the route map filtering capability that exists for other routing protocols to filter routes being redistributed into their protocol. For more details about understanding and configuring route maps, see the Enabling Policy Routing section of the "Configuring IP Routing Protocol-Independent Features" chapter of the Cisco IOS XE IP Routing Protocols Configuration Guide, Release 2.

New match options allow EIGRP to filter internal and external routes based on source protocols, to match a metric against a range, and to match on an external protocol metric.

EIGRP can be configured to filter traffic using a route map and the redistribute or distribute-list commands. Using a route map with the redistribute command allows routes that are redistributed from the routing table to be filtered with a route map before being admitted into an EIGRP topology table. Routes that are dynamically received from, or advertised to, EIGRP peers can be filtered by adding a route map option to the distribute-list command.

A route map may be configured with both the redistribute and the distribute-list commands in the same routing process. When a route map is used with a distribute-list command that is configured for inbound or outbound filtering, route packets that are learned from or advertised to EIGRP peers can be processed with the route map to provide better control of route selection during the route exchange process. Redistribution serves as a mechanism to import routes into the EIGRP topology table from a routing table. A route map configured with the redistribute command adds flexibility to the redistribution capability and results in a more specific redistributed route selection.

In summary, demands for EIGRP to interoperate with other protocols and flexibility in fine-tuning network operation necessitate the capability to filter traffic using a route map.

How to Configure EIGRP Support for Route Map Filtering

This section contains the following tasks:

Configuring EIGRP Metrics Using a Route Map (required)

Verifying EIGRP Metrics (optional)

Configuring EIGRP Metrics Using a Route Map

Perform this task configure EIGRP metrics using a route map. In the Detailed Steps below, the EIGRP metrics used for filtering are configured within a route map. The first match clause defines EIGRP routes that contain an external protocol metric between 400 and 600 inclusive; the second match clause defines EIGRP external routes that match a source protocol of BGP and the autonomous system 45000. When the two match clauses are true, a tag value of the destination routing protocol is set to 5. This route map can be used with the distribute-list command, see the "Configuring EIGRP Metrics Using a Route Map: Examples" section for an example configuration.

SUMMARY STEPS

1. enable

2. configure terminal

3. route-map map-tag [permit | deny] [sequence-number]

4. match metric {metric-value | external metric-value} [+- deviation-number]

5. match source-protocol source-protocol [autonomous-system-number]

6. set tag source-protocol [autonomous-system-number]

7. exit

8. router eigrp as-number

9. network ip-address

10. distribute-list route-map map-tag in

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

route-map map-tag [permit | deny] [sequence-number]

Example:

Router(config)# route-map metric_range

Enters route-map configuration mode.

Step 4 

match metric {metric-value | external metric-value} [+- deviation-number]

Example:

Router(config-route-map)# match metric external 500 +- 100

Specifies a match clause that redistributes EIGRP routes that match an internal or external protocol metric.

metric-value—Internal protocol metric, which can be an EIGRP five-part metric. The range is from 1 to 4294967295.

external—External protocol metric. The range is from 1 to 4294967295.

+- deviation-number—(Optional) Represents a standard deviation. The deviation can be any number. There is no default.

In this example, EIGRP routes that contain an external protocol metric between 400 and 600 inclusive are redistributed.

Note When you specify a metric deviation with the + and - keywords, the router will match any metric that falls inclusively in that range.

Note The external protocol metric is not the same as the EIGRP assigned route metric which is a figure computed from EIGRP vectorized metric components (delay, bandwidth, reliability, load, and MTU).

Step 5 

match source-protocol source-protocol [autonomous-system-number]

Example:

Router(config-route-map)# match source-protocol bgp 45000

Specifies a match clause that redistributes EIGRP external routes that match a source protocol.

source-protocol—Protocol to match. The valid keywords are bgp, connected, eigrp, isis, ospf, rip, and static. There is no default.

autonomous-system-number—(Optional) Autonomous system number. The autonomous-system-number argument is not applicable to the connected, static, and rip keywords. The range is from 1 to 65535. There is no default.

In this example, EIGRP external routes that match a source protocol of BGP and the autonomous system 45000.

Step 6 

set tag tag-value

Example:

Router(config-route-map)# set tag 5

Sets a tag value of the destination routing protocol when all the match criteria of a route map are met.

In this example, the tag value of the destination routing protocol is set to 5.

Step 7 

exit

Example:

Router(config-route-map)# exit

Exits route map configuration mode and returns to global configuration mode.

Step 8 

router eigrp as-number

Example:

Router(config)# router eigrp 1

Configures the EIGRP routing process.

Step 9 

network ip-address

Example:

Router(config-router)# network 172.16.0.0

Specifies a network for the EIGRP routing process.

Step 10 

distribute-list route-map map-tag in

Example:

Router(config)# distribute-list route-map metric_range in

Filters networks received in updates.

This example uses a route map to filter the networks. The route map named "metric_range" was identified in Step 3 above.

Verifying EIGRP Metrics

To verify that both the EIGRP metric and the external protocol metrics have been configured, perform the following steps.

SUMMARY STEPS

1. enable

2. show ip eigrp topology [autonomous-system-number | ip-address [/mask]] [active | all-links | detail-links | pending | summary | zero-successors]

DETAILED STEPS


Step 1 enable

Enables privileged EXEC mode. Enter your password if prompted.

Router# enable

Step 2 show ip eigrp topology [autonomous-system-number | ip-address [/mask]] [active | all-links | detail-links | pending | summary | zero-successors]

Use this command to display the internal EIGRP metrics for a specified IP address, for example:

Router# show ip eigrp topology 172.16.1.0/24

IP-EIGRP (AS 45000): Topology entry for 172.16.1.0/24
  State is Passive, Query origin flag is 1, 1 Successor(s), FD is 2169856
  Routing Descriptor Blocks:
  0.0.0.0 (Serial4/0), from Connected, Send flag is 0x0
      Composite metric is (2169856/0), Route is Internal
      Vector metric:
        Minimum bandwidth is 1544 Kbit
        Total delay is 20000 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 0

In the following example, the external EIGRP metrics for a specified IP address are displayed:

Router# show ip eigrp topology 192.168.1.0/24

IP-EIGRP (AS 45000): Topology entry for 192.168.1.0/24
  State is Passive, Query origin flag is 1, 1 Successor(s), FD is 2169856
  Routing Descriptor Blocks:
  0.0.0.0 (Serial4/0), from Connected, Send flag is 0x0
      Composite metric is (2169856/0), Route is External
      Vector metric:
        Minimum bandwidth is 1544 Kbit
        Total delay is 20000 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 1
        External data:
        Originating router is 10.89.245.1 
        AS number of route is 0
        External protocol is Connected, external metric is 0
        Administrator tag is 0 (0x00000000)

Configuration Examples for EIGRP Support for Route Map Filtering

This section contains the following configuration example:

Configuring EIGRP Metrics Using a Route Map: Examples

Configuring EIGRP Metrics Using a Route Map: Examples

The following example shows how to configure a route map to match an EIGRP external protocol metric route with an allowable deviation of 100, a source protocol of BGP, and an autonomous system 45000. When the two match clauses are true, the tag value of the destination routing protocol is set to 5. The route map is used to distribute incoming packets for an EIGRP process.

route-map metric_range
 match metric external 500 +- 100
 match source-protocol bgp 45000
 set tag 5
!
router eigrp 1
 network 172.16.0.0
 distribute-list route-map metric_range in

The following example shows how to configure a route map to match EIGRP routes with a metric of 110, 200, or an inclusive range of 700 to 800. When the match clause is true, the tag value of the destination routing protocol is set to 10. The route map is used to redistribute EIGRP packets.

route-map metric_eigrp
 match metric 110 200 750 +- 50
 set tag 10
!
router eigrp 1
 network 172.21.1.0/24
 redistribute eigrp route-map metric_eigrp

Additional References

The following sections provide references related to the EIGRP Support for Route Map Filtering feature.

Related Documents

Related Topic
Document Title

EIGRP overview and configuration

"Configuring EIGRP" module

IP routing commands including syntax, usage guidelines, and examples

Cisco IOS IP Routing Protocols Command Reference


Standards

Standard
Title

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


MIBs

MIB
MIBs Link

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

To locate and download MIBs for selected platforms, Cisco IOS XE software releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs


RFCs

RFC
Title

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


Technical Assistance

Description
Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/techsupport


Feature Information for EIGRP Support for Route Map Filtering

Table 1 lists the release history for this feature.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS XE software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.


Note Table 1 lists only the Cisco IOS XE software release that introduced support for a given feature in a given Cisco IOS XE software release train. Unless noted otherwise, subsequent releases of that Cisco IOS XE software release train also support that feature.


Table 1 Feature Information for EIGRP Support for Route Map Filtering 

Feature Name
Releases
Feature Information

EIGRP Support for Route Map Filtering

Cisco IOS XE
Release 2.1

The EIGRP Support for Route Map Filtering feature enables EIGRP to interoperate with other protocols by filtering inbound and outbound traffic based on complex route map options. In addition to the existing route map facility, several extended filtering options are introduced to provide EIGRP-specific match choices.

In Cisco IOS XE Release 2.1, this feature was introduced on the Cisco ASR 1000 Series Aggregation Services Routers.

The following commands were introduced or modified by this feature: match metric (IP), match source-protocol, show ip eigrp topology.