The network diagran is as follow:
Site X--<ADSL>---<ADSL>-- Site A--<C2950-1>======<C2950-2>--Site B
There are two sets of Catalyst 2950G-48{IOS 12.1(14)EA1} in our sites. It is located in different site(A and B). Two devices are connected by two pairs of single-mode fibler(1000BaseLH). Two gigabitethernet interfaces are configured as portchannel/isl trunk on each Catalyst 2950G-48.There two sets of server in echo Catalyst 2950G-48. There are one ADSL VPN connect to Site X.
The problem is:
1. User in site X can access server in site A but can't access server in site B.
2. Server in site A can access user site X and site B.
3. Servers in site A and B can access each other.
4. When the problem is happend, ARP tables of Catalys 2950G-48 and ADSL ATU-R all correct.
5. If I disconnected one pair of fiber, all connection are OK.
6. After 3 days, the same problem is happened again. If I remove port-channel configuration, it is OK.
Why? Thanks.
Thomas
