[c-nsp] BGP/EIGRP Route Determination

Brian Tate tatebk at hotmail.com
Fri Dec 23 01:34:24 EST 2011

Hey All,
I'm experiencing an issue with re-establishing BGP routes as preferred over EIGRP, after failure/restore.

Network diagram & scheme:

The text in the middle of the diagram indicates the route summarization & static route injections performed on each firewall.  
Both FW's are injecting/summarizing the same routes into EIGRP, with FW-B having interface delays & metrics to make it the backup.
Likewise, Rtrs A & B are both redistributing EIGRP into BGP & BGP into EIGRP

In a normal state, all traffic flows thru Rtr & FW-A.
1. Failure occurs at Rtr-A
2. All routing quickly reconverges to use Rtr & FW-B
<no problem to this point>
3. Service restores on Rtr-A
4. (problem) 75% of the time, Rtr-B does not re-select the BGP routes as preferred routes
- about 25% it will reconverge routes to use BGP
- the moment I issue a 'clear ip eigrp neig' on Rtr-B, the correct BGP routes become preferred

What can I do to ensure the BGP routes are always preferred, without the manual EIGRP intervention?
Below is the current config on Rtr B.

router eigrp 1
 redistribute bgp 68501 metric 5000 10 255 1 1500 route-map BGPtoEIGRP
 offset-list 1 in 10000 Vlan999
 passive-interface default
 no passive-interface Vlan999
router bgp 68501
 no synchronization
 bgp log-neighbor-changes
 bgp redistribute-internal
 network mask
 network mask
 redistribute eigrp 1 route-map EIGRPtoBGP
 neighbor x.x.x.x remote-as 13000
 neighbor x.x.x.x fall-over bfd
 neighbor x.x.x.x weight 50000
 no auto-summary

Thanks in advance
- Tate

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