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How to exclude ip subnet from eigrp

HI guys, I have           --[switchA]---[swB]--[coreswitch] ----[ASRwan01]-linkX-- [routerC] connected to other sites via mpls and  dmvpn . I have picture attached. 

 on the core switch i have eigrp for networks 10.0.0.0 by default summarized (there is  not no auto summary command) and advertised to everyone. RouterC uses ASRwan01 as exit to Internet. RouterC has 2 connections to ASRwan01 : direct linkX and trough [switchA]-[switchB]-[coreswitch] linkY .

LinkY ends : 10.137.95.18 on the coreswitch and 10.137.95.17 on the routerC. 

I need to exclude subnet 10.137.95.0 from summarization on the coreswitch and send it trough another port (for instance gi0/2) of the coreswitch . It should connect from coreswitch-10.137.95.18  to swB-swA via vlan 100 to another routerC dot1q 10.137.95.17  interface (backup link for router C ) , so routerC will have 2 connections (linkX and linkY) to ASRwan01 .  I want to increase  delay on the second port/linkY  of routerC so that route will be secondary . If linkX down routerC must have access to internet over llinkY .  Right now when I do sho ip route 10.137.95.17 on the core its sending to ASRwan01 but I must have it as "connected" . 

Is it possible to separate this subnet in this case, how  ? Or I need to have another eigrp process ? I saw some route leak example but could not figure out how to use in my case . ... 

    Thank you 

5 Replies 5

Philip D'Ath
VIP Alumni
VIP Alumni

What about disabling auto-summary at the "router eigrp" level, and then enable it on the interface level.  Enable it on the interface on the links that go to remote WAN sites, use something like (assuming an EIGRP process ID of 1):

interface a b/c

  ip summary-address eigrp 1 10.0.0.0 255.0.0.0

Or, better still, if all the remote sites only connect back to you, summarise a default route:

interface a b/c

  ip summary-address eigrp 1 0.0.0.0 0.0.0.0

Now the network core has a complete and detailed routing table.

I didn't implement ur advice yet , but :

sho ip protocol shows auto-summ disabled, as I found new version after 12.2.33 they have disabled by default auto-summary but when u do sho run it doesnt show that disabled . Sorry I confused you . 

But anyway sho ip cef 10.137.95.17 and sho ip route 10.137.95.0 on the coreswitch shows path to ASR [coreswitch] ----[ASRwan01] 

not as connected to router_C directly (physically ) , switchA and switch B can see each others by vlan 100 (subnet 10.137.95.0/24). But coreswitch cant ping switchB vl100 interface but see mac address in vl 100 , and router C cant ping switchA vl100 interface, cause ip route shows path to LinkX. 

How can I separate 10.137.95.0/24 and push it over LinkY ? Is ur previous advice will work still if i also add "ip summary-address eigrp 1 10.xx.0.0 255.255.0.0 leak-map LEAK, where LEAK map has ip of 10.137.95.0"?    

Are you sure routerc is advertising 10.137.95.0/24 ?  Have you got a network statement on it so it is being advertised?

Yup, there is network for that subnet under  eigrp 1. 

3750-COR01# sho ip eigrp top 10.137.95.16/30
EIGRP-IPv4 Topology Entry for AS(1)/ID(10.128.127.17) for 10.137.95.16/30
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 7680
Descriptor Blocks:
0.0.0.0 (Vlan100), from Connected, Send flag is 0x0
Composite metric is (7680/0), route is Internal
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 200 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 0
Originating router is 10.128.127.17 <--this is ip of this coreswitch

----

3925-WAN02# sho ip eigrp top 10.137.95.16/30
EIGRP-IPv4 Topology Entry for AS(1)/ID(10.128.127.34) for 10.137.95.16/30
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 30720
Descriptor Blocks:
0.0.0.0 (GigabitEthernet0/2.100), from Connected, Send flag is 0x0
Composite metric is (30720/0), route is Internal
Vector metric:
Minimum bandwidth is 100000 Kbit
Total delay is 200 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 0
Originating router is 10.128.127.34 <---this is ip of this router 
EIGRP-IPv4 Topology Entry for AS(2)/ID(10.128.127.34)
%Entry 10.137.95.16/30 not in topology table

-Is it because of I have delay for this route set up to make it secondary ? 

No, it wont be because of the weight.  The route is completly missing from 3925-WAN02.

Either routes are being summarise, that should not be (did you change the summarisation yet?), or it is not talking EIGRP on both interfaces.

We really need to see the configs to take it a step further.

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