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Community Member

EIGRP route preference?

How can I force EIGRP to prefer external vs internal route? I have used delay in the past to influence route selection but here you can see everything but internal vs external is better via 10.100.25.1. The config below is from a core router with 1 gig connection to another core router (10.100.25.1) which has a 100mb connection and a static route to the 172.22.0.0/15 network..  10.99.2.11 is DMVPN router that has a DMVPN tunnel to 172.22.0.0/15.  I want to prefer the external route over the DMVPN route but not sure how to do that?   

!

P 172.22.0.0/15, 1 successors, FD is 1600512
        via 10.99.2.11 (1600512/1600256), Vlan99
        via 10.100.25.1 (28416/28160), GigabitEthernet1/1

!

EIGRP-IPv4 Topology Entry for AS(9999)/ID(10.0.25.1) for 172.22.0.0/15
  State is Passive, Query origin flag is 1, 1 Successor(s), FD is 1600512
  Descriptor Blocks:
  10.99.2.11 (Vlan99), from 10.99.2.11 Send flag is 0x0
      Composite metric is (1600512/1600256), route is Internal
      Vector metric:
        Minimum bandwidth is 8000 Kbit
        Total delay is 50020 microseconds
        Reliability is 255/255
        Load is 16/255
        Minimum MTU is 1400
        Hop count is 2
  10.100.25.1 (GigabitEthernet1/1), from 10.100.25.1, Send flag is 0x0
      Composite metric is (28416/28160), route is External
      Vector metric:
        Minimum bandwidth is 100000 Kbit
        Total delay is 110 microseconds
        Reliability is 255/255
        Load is 10/255
        Minimum MTU is 1500
        Hop count is 1
        Originating router is 10.100.25.1
      External data:
        AS number of route is 0
        External protocol is Static, external metric is 0
        Administrator tag is 0 (0x00000000)

 

1 ACCEPTED SOLUTION

Accepted Solutions
VIP Super Bronze

Have a look at this post. It

Have a look at this post. It might be helpful

https://supportforums.cisco.com/discussion/11165101/eigrp-prefer-external-routes-vs-internal-routes

HTH

5 REPLIES
VIP Super Bronze

Have a look at this post. It

Have a look at this post. It might be helpful

https://supportforums.cisco.com/discussion/11165101/eigrp-prefer-external-routes-vs-internal-routes

HTH

Cisco Employee

Additional links:https:/

Additional links:

https://supportforums.cisco.com/discussion/11213491/eigrp-route-preference

https://supportforums.cisco.com/discussion/11189786/eigrp-influencing-routes

 

HTH

 

Community Member

Hi,  You might also want to

Hi, 

 

You might also want to check some of the documentation on the Cisco website about this as well. You can find some helpful info here:

http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/8651-21.html

 

The sections titled "Adjusting the Administrative Distance" and "How Metrics Determine the Routing Process" give a high-level on what those changes can do to change some of the routing paths. I'd advise caution with changing the AD though: that can cause some loops in the network if used improperly. Under that there is another link that helps you configure the AD, tuning it to what you might need. 

 

Hope that helps. 

Community Member

I have tried per this

I have tried per this documentation:  http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/16406-eigrp-toc.html#statictointerface as noted below. It worked in the lab but did not in production.  In PROD the exact same steps never made the static route appear as 'internal.'

 

 

Community Member

I figured out how to do this

I figured out how to do this on my own in the lab....But it doesn't work in production.  (12.x lab vs 15.x prod)

1. Add route to interface instead of next hop IP

ip route 172.22.0.0 255.254.0.0 gi1/39 vs ip route 172.22.0.0 255.254.0.0 xx.xx.xx.xx

2. Add the matching network to eigrp process and disable auto-summary:

router eigrp 9999

network 172.22.0.0 0.1.255.255

no auto-summary

You can see where the router via 10.100.25.1 is now showing as internal vs external in my previous post.  This is only because I don't have EIGRP running on the 172.22.0.0/15 network, once I do I assume this problem will go away.  


IP-EIGRP (AS 9999): Topology entry for 172.22.0.0/15
  State is Passive, Query origin flag is 1, 1 Successor(s), FD is 284160
  Routing Descriptor Blocks:
  10.100.25.1 (GigabitEthernet1/1), from 10.100.25.1, Send flag is 0x0
      Composite metric is (284160/28160), Route is Internal
      Vector metric:
        Minimum bandwidth is 10000 Kbit
        Total delay is 1100 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 1
  10.99.2.11 (vlan99), from 10.99.2.11, Send flag is 0x0
      Composite metric is (13171200/13145600), Route is Internal
      Vector metric:
        Minimum bandwidth is 8000 Kbit
        Total delay is 502000 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1400
        Hop count is 2

 

   

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