Help with EIGRP on Cat 6500

lee.messenger · ‎03-12-2007

Hi,

I have 2 x Cat 6513's which make up one of the core's of my network. They are connected via a L2 Etherchannel and share the same VLAN database. Both switches have the same VLAN interfaces which are configured as HSRP groups.

There are about a dozen L3 WAN links terminating on the routers which connect to remote sites.

I am currently running EIGRP on both routers, and am running EIGRP on all VLAN's on the 2 routers as well as the L3 WAN links.

I have been thinking about this configuration recently and have come to the conclusion that I don't need to be running EIGRP on the VLAN's as this creates an unnecessary amount of EIGRP neighbor relationships.

I have also started to notice the neighbors bouncing, and some routes becoming SIA for no real reason.

Could someone please advise whether this is a good idea and what should be the best practise for running EIGRP on these switches with many VLAN's.

Thanks

Lee

bbravo · ‎03-12-2007

Lee,

Configure "passive interface default" under your EIGRP statement, then only advertise your router uplinks and your core network, be careful to do the "no passive interface" for all networks that need tobe advertised, i.e:

router eigrp 55

passive-interface default

no passive-interface Vlan21

no passive-interface GigabitEthernet7/46

no passive-interface GigabitEthernet7/47

no passive-interface GigabitEthernet7/48

network 172.18.0.0

no auto-summary

Jon Marshall · ‎03-13-2007

Hi

I agree with the other poster. In our datacentres what we normally do is allocate two vlans purely for EIGRP neighborships between the 2 6500 switches. These vlans don't run HSRP and have no physical ports in them. Then we make passive all other vlan interfaces on the switches.

All other links ie. to separate routers are not made passive obviously.

Makes it a lot easier to troubleshoot when you are under pressure.

HTH

Jon

lee.messenger · ‎03-13-2007

Guys,

Thanks very much for your advice, makes perfect sense to me now

Cheers

Lee