Route Aggregation stops working

[Nick_Doropoulos]

Hi fellow members,

Has anybody ever had any issues with route aggregation which "broke" after swapping the network's core switch? I am basically referring to a scenario where a single route was used for the internal network and then, after replacing the network switches, reply traffic was not getting back to the internal network and the issue was resolved only by creating individual routes.

I've been having difficulty finding any relevant sks about this and I've already consulted the advanced routing guide without any luck.

Any help would be much appreciated as always.