4506 periodically deletes all connected vlan interfaces from routing table

grimsby.moraine · ‎12-02-2009

I have a 4506 with SupIV, cat4000-i9s-mz.121-19.EW1.bin.

Every few hours (once a day, but not at the same time very day) the 4506 removes all connected interfaces from the routing table, then adds them a few seconds later. Why is it doing this and can i stop it?

"debug ip routing" shows:

Nov 28 15:55:40 192.168.2.1 1116: Nov 28 15:55:40 GMT: RT: interface Vlan10 removed from routing table
Nov 28 15:55:40 192.168.2.1 1117: Nov 28 15:55:40 GMT: RT: del 192.168.10.0 via 0.0.0.0, connected metric [0/0]
Nov 28 15:55:40 192.168.2.1 1118: Nov 28 15:55:40 GMT: RT: delete network route to 192.168.10.0
Nov 28 15:55:40 192.168.2.1 1119: Nov 28 15:55:40 GMT: is_up: 0 state: 0 sub state: 1 line: 0
Nov 28 15:55:40 192.168.2.1 1120: Nov 28 15:55:40 GMT: RT: interface Vlan11 removed from routing table
Nov 28 15:55:40 192.168.2.1 1121: Nov 28 15:55:40 GMT: RT: del 192.168.11.0 via 0.0.0.0, connected metric [0/0]
Nov 28 15:55:40 192.168.2.1 1122: Nov 28 15:55:40 GMT: RT: delete network route to 192.168.11.0
Nov 28 15:55:41 192.168.2.1 1123: Nov 28 15:55:40 GMT: is_up: 0 state: 0 sub state: 1 line: 0
Nov 28 15:55:41 192.168.2.1 1124: Nov 28 15:55:40 GMT: RT: interface Vlan12 removed from routing table
Nov 28 15:55:41 192.168.2.1 1125: Nov 28 15:55:40 GMT: RT: del 192.168.12.0 via 0.0.0.0, connected metric [0/0]

Nov 28 15:56:17 192.168.2.1 1316: Nov 28 15:56:16 GMT: RT: add 192.168.10.0/24 via 0.0.0.0, connected metric [0/0]
Nov 28 15:56:17 192.168.2.1 1317: Nov 28 15:56:16 GMT: RT: interface Vlan10 added to routing table
Nov 28 15:56:17 192.168.2.1 1318: Nov 28 15:56:16 GMT: is_up: 1 state: 4 sub state: 1 line: 1
Nov 28 15:56:17 192.168.2.1 1319: Nov 28 15:56:16 GMT: RT: add 192.168.11.0/24 via 0.0.0.0, connected metric [0/0]
Nov 28 15:56:17 192.168.2.1 1320: Nov 28 15:56:16 GMT: RT: interface Vlan11 added to routing table
Nov 28 15:56:17 192.168.2.1 1321: Nov 28 15:56:16 GMT: is_up: 1 state: 4 sub state: 1 line: 1
Nov 28 15:56:17 192.168.2.1 1322: Nov 28 15:56:16 GMT: RT: add 192.168.12.0/24 via 0.0.0.0, connected metric [0/0]
Nov 28 15:56:17 192.168.2.1 1323: Nov 28 15:56:16 GMT: RT: interface Vlan12 added to routing table

Roman Rodichev · ‎12-02-2009

Do you see in the logs if the Layer 3 SVI VLAN interface always goes down at the same time. If the last port in the VLAN goes down and the VLAN is not trunked, the Layer 3 SVI will go down (it can be configured to always stay up), and the connected route will disappear.

Regards,

Roman

ieMentor Corp.

grimsby.moraine · ‎12-14-2009

No, it's not that. Your suggestion did make me check layer2 but it doesn't seem to be that either. All VLANs are trunked to the next switch so they sould go down. The log shows that no interfaces go down.