When a Catalyst 3750 stack master fails or leaves the stack, a cross-stack EtherChannel in trunk mode running Link Aggregation Control Protocol (LACP) protocol might stop forwarding traffic on some VLANs.
The workaround is to enable the stack-mac persistent feature by using the stack-mac persistent timer global configuration command. You can also use the shutdown interface configuration command and then the no shutdown command on the EtherChannel interface.
Network Infrastructure: LAN Routing and Switching
I have upgrade a Catalyst 37024 TS 2 switch stack to 12.2(25)SED1 from 12.1(14)EA. The switch has an Alpha Server Custer connected to it the cluster has two servers each having two nics . There is a active server which has an application IP address and each server has a Server IP address one nic active ata time.
All worked ok upto the upgrade. Now every night when the backup runs noone can access the application ip address or the acive server address but te offline server is pingable. This is only for devices outside the serrver VLAN. Devices within the server VLAN can hapily ping any address.
I thought this was arouing issue but all looks ok and the offline server can be pinged from any where.
the active server nics areon 1/0/20 and 2/0/24
Any one have any ideas?
