EIGRP route path selection

[thiagosct]

Hi Guys,

Just seeking some advice in how I would be able to manually set EIGRP to route through a specific link as both routers have 1Gb link. I understand EIGRP calculate it’s metrics based on bandwidth + delay.

I would like to specific route traffic from vlan 10 to vlan 20 using the first link (Gig1/0/23) without compromising the other traffic that goes on (Gig1/0/24) interface that I changed the delay settings. Maybe route poison int Gig1/0/24 telling router 2 is 10 hops away?, I am not sure     Is there any way we can do that? Any help would be appreciated!

Thank you,

[Richard Burts · Accepted solution]

I find your post to be somewhat confusing. Your post talks about VLAN 10 and VLAN 20 but there is no mention of these VLANs in the diagram. And the diagram shows networks 192.168.1.x and 192.168.2.x but no mention of whether these networks are associated with any VLAN.

I might think that the simple solution would be to specify a delay on Gig1/0/24 higher than what is specified (or default) on Gig 1/0/23. A more sophisticated solution might be to configure an offset list in EIGRP to make Gig1/0/24 higher than Gig1/0/23.

If you could give us a better understanding of your topology and of your requirements then perhaps we could provide better answers.

HTH

Rick

[thiagosct]

Hi Richard,

Thanks for your reply and sorry for the confusion, I am trying to do is to  configure R1 EIGRP settings manually  to use always gig1/0/23 to route VLAN 10 traffic to R2 network, here is the new diagram

S1 - show ip route

C    192.168.10.0/24 is directly connected, Vlan10
D    192.168.20.0/24
           [90/3072] via 192.168.2.2, 01:12:50, GigabitEthernet1/0/24
           [90/3072] via 192.168.1.2, 01:12:50, GigabitEthernet1/0/23
C    192.168.1.0/24 is directly connected, GigabitEthernet1/0/23
C    192.168.2.0/24 is directly connected, GigabitEthernet1/0/24

S2 - show ip route

D    192.168.10.0/24
           [90/3072] via 192.168.2.1, 01:11:32, GigabitEthernet2/0/24
           [90/3072] via 192.168.1.1, 01:11:32, GigabitEthernet2/0/23
C    192.168.20.0/24 is directly connected, Vlan20
C    192.168.1.0/24 is directly connected, GigabitEthernet2/0/23
C    192.168.2.0/24 is directly connected, GigabitEthernet2/0/24

Can you give me an exemple how to use  offset listi in this case please?

Regards,

TC

[manish arora]

In addition to what Sir Rick said :-

You can also TAG the routes on the routers and then filter the untag routes using route-map filter with distribute list on per interface basic. for ex from one of my LAB setup ( please test before making changes to the production) :-

using route maps to filter routes :-
Advertising router setting a tag on the route :-

route-map Connected_to_eigrp permit 10
  match interface Loopback2
  set tag 100
router eigrp 100
redistribute connected route-map Connected_to_eigrp
redistribute static
network 155.1.0.0 0.0.0.255
network 155.1.5.0 0.0.0.255
network 155.1.45.0 0.0.0.255
network 155.1.55.0 0.0.0.255
no auto-summary

Reciving router filter everything but a route with Tag value 100 :-

route-map Filter permit 10
match tag 100
router eigrp 100
network 155.1.0.0 0.0.0.255
network 155.1.4.0 0.0.0.255
network 155.1.45.0 0.0.0.255
distribute-list route-map Filter in Serial0/0
distribute-list route-map Filter in Serial0/1
no auto-summary

Gateway of last resort is not set

     155.1.0.0/24 is subnetted, 4 subnets
D EX    155.1.155.0 [170/2297856] via 155.1.0.5, 00:05:01, Serial0/0
C       155.1.0.0 is directly connected, Serial0/0
C       155.1.4.0 is directly connected, Loopback0
C       155.1.45.0 is directly connected, Serial0/1
r4#

Manish

[thiagosct]

Hi Richard,

I used offset-list on Gig1/0/24 and worked! thanks for your help

router eigrp 10
redistribute connected
offset-list 1 out 20 GigabitEthernet1/0/24
network 192.168.1.0
network 192.168.2.0
network 192.168.10.0
network 192.168.20.0
no auto-summary
!
ip default-gateway 192.168.1.1
ip classless
ip http server
!
access-list 1 permit 192.168.10.0 0.0.0.255

now GigabitEthernet1/0/23 has  lower metrics

R1#show ip eigrp topology 192.168.20.0
IP-EIGRP (AS 10): Topology entry for 192.168.20.0/24
  State is Passive, Query origin flag is 1, 1 Successor(s), FD is 3072
  Routing Descriptor Blocks:
  192.168.1.2 (GigabitEthernet1/0/23), from 192.168.1.2, Send flag is 0x0
      Composite metric is (3072/2816), Route is Internal
      Vector metric:
        Minimum bandwidth is 1000000 Kbit
        Total delay is 20 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 1
  192.168.2.2 (GigabitEthernet1/0/24), from 192.168.2.2, Send flag is 0x0
      Composite metric is (3092/2836), Route is Internal
      Vector metric:
        Minimum bandwidth is 1000000 Kbit
        Total delay is 20 microseconds
        Reliability is 255/255
        Load is 1/255
        Minimum MTU is 1500
        Hop count is 1

Regards,

TC

[Richard Burts]

TC

I am glad that you got it to work and that my suggestion was helpful in finding the solution. It makes the forum more useful when people can read about an issue and can read a solution to that issue. You have identified an issue and the solution to that issue. If you were to mark this issue as answered/resolved it would help other readers to know that a solution has been found.

HTH

Rick