[c-nsp] spanning-tree flaps with BVI routed interface

[Brian]

Has anyone experienced this before?


On 3/9/07, Brian <bms314 at gmail.com> wrote:
>
> I have a 2811 multihomed to two 4507 core routers.  The router is
> configured with a BVI to provide redundancy to the core.  However, I
> continually see a host flapping message in the core router every 30 seconds.
>
>
> Mar  9 15:18:38 Central: %C4K_EBM-4-HOSTFLAPPING: Host 00:1A:2F:C7:2E:50
> in vlan 697 is flapping between port Gi7/31 and port Po27
> Mar  9 15:19:08 Central: %C4K_EBM-4-HOSTFLAPPING: Host 00:1A:2F:C7:2E:50
> in vlan 697 is flapping between port Gi7/31 and port Po27
> Mar  9 15:19:38 Central: %C4K_EBM-4-HOSTFLAPPING: Host 00:1A:2F:C7:2E:50
> in vlan 697 is flapping between port Gi7/31 and port Po27
>
> Gi7/31 is the physical connection on the 1st 4507 and Po27 is the link
> between the 4507's.  The 2nd 4507 has similar log messages.
>
>
> The config of the 2811 is as follows:
>
>
> interface FastEthernet0/0
>  no ip address
>  duplex full
>  speed 100
>  bridge-group 1
>
> interface FastEthernet0/1
>  no ip address
>  duplex full
>  speed 100
>  bridge-group 1
>
> interface BVI1
>  ip address 204.X.X.X 255.255.255.224
>
> bridge 1 protocol ieee
> bridge 1 route ip
>
>
> I believe spanning-tree should block one of the ports and keep the other
> port in a forwarding state.  It seems to be bouncing back and forth.  Any
> ideas as to what could be causing this behavior and/or how to correct it?
>
> Thanks,
> Brian
>