Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Community Member

EIGRP Route Recalculation

Will a router invalidate it's routing table while EIGRP is recalculating ?

1 REPLY

Re: EIGRP Route Recalculation

Hello,

in general the answer is: No.

The IP routing table will not be invalid.

EIGRP will start to "recalculate" when the current next hop for a network becomes unreachable or the current next hop announces an EIGRP update for a network stating this network is unreachable.

In this case EIGRP will use the "second best" route immediately, if it is "feasible", i.e. the advertised distance of the second best is still better than the metric of the (lost) network on this router.

In case there is no feasible successor, EIGRP will start the query process. Until all queries have been replied by the neighbors the route is "active". An active route is not in the IP routing table, thus the network is not reachable for user traffic.

All this is done on a per-network basis. So the rest of the IP routing table remains in place and unchanged.

Hope this helps! Please rate all posts.

Regards, Martin

187
Views
0
Helpful
1
Replies
CreatePlease to create content