darrenhubbard
Technical User
I am testing some eigrp authentication and am getting some very strange behaviour. Three routers, each with an ethernet connection sitting on the same subnet. 1st router also has a serial connection connected elsewhere in the network. 3rd router has a loopback pretending to be a "rogue" network. All routers can see each has eigrp neighbors and are sharing the correct routes etc etc. Now, the unusual behaviour:
1) Authentication on routers 1 and 2 is turned on (1 key, never expiring). Despite this, these routers can still see the routes advertised by router 3 and still consider it an eigrp neighbor unless neighbors and/or routes are manually cleared.
2) After this the key on router 2 was changed. Routers 1 and 2 still happily sharing routes until neighbors or routes are cleared. Router 3 remains out of the equation still. Key is changed back and routers immediately start sharing routes again.
3) The key on router 2 was then set to expire (both send and accept) a few minutes later. On expiry of the key, router 2 momentarily loses all routes and neighbors and then immediately regains them PLUS the routes on the "rogue" network on router 3!!!!
Now, maybe I'm misunderstanding how the eigrp authentication works but I assumed that with authentication turned on, without matching keys the routers wouldn't see each other as neighbors, exchange routes or anything to do with eigrp!!!
This is driving me nuts, any help would be appreciated...
TIA,
Darren
1) Authentication on routers 1 and 2 is turned on (1 key, never expiring). Despite this, these routers can still see the routes advertised by router 3 and still consider it an eigrp neighbor unless neighbors and/or routes are manually cleared.
2) After this the key on router 2 was changed. Routers 1 and 2 still happily sharing routes until neighbors or routes are cleared. Router 3 remains out of the equation still. Key is changed back and routers immediately start sharing routes again.
3) The key on router 2 was then set to expire (both send and accept) a few minutes later. On expiry of the key, router 2 momentarily loses all routes and neighbors and then immediately regains them PLUS the routes on the "rogue" network on router 3!!!!
Now, maybe I'm misunderstanding how the eigrp authentication works but I assumed that with authentication turned on, without matching keys the routers wouldn't see each other as neighbors, exchange routes or anything to do with eigrp!!!
This is driving me nuts, any help would be appreciated...
TIA,
Darren