Any help or advise with this one would be appreciated!
I have a network across two floors (11th and 12th).
The 11th floor is the core network with 2 x 3750G switches with enhanced IOS. These switches have 3 vlans, WAN (vlan 100), Voice (vlan 10) and Data (vlan 20). I also have a 3560 switch connected to the core with a dot1q trunk (native vlan 1)
The 12th floor consists of 3 x 3560-48 10/100 switches and connect to the 11th floor via 2 x 2gb etherchannels configured to carry all vlans across a dot1q trunk (native vlan 1) One channel to each of the 3750's.
Problem: When people work on the 12th floor they complain of a slow network, however voice call quality is good, so this only effects the data vlan. When these people move to the 11th floor everything is fine.
My server team has ruled out any issues with AD/ Domain controllers so this has landed with me and unfortunately I can see no configuration issues or problems. Can anyone suggest what to look for?
Verified so far:
STP is as expected, blocking in the correct place. CDP topology is as I would expect and the etherchannels are using native vlan 1. The port channels are seeing no errors/dropped packets etc.
If any more info is required please ask.