I'm having a problem in which client computers are pulling ip addresses from the wrong DHCP server.
We have a hub and spoke topology and each site is connected to the hub via Metro Ethernet. 3750G core switches are responsible for routing at each site and we are using EIGRP. Each site also has it's on DHCP server.
Some sites are really close to each other so we have setup a backup link via fiber just in case the Metro Ethernet circuit goes down at that particular site. We configured both connecting ports on the 3750's as trunk ports but we are having a problem with clients from site 1 occasionally pulling ip addresses from the DHCP server at site 2. This only happens when we have the backup link connected.
We have vlans created at each site with the ip helper-address pointing to the correct DHCP server.
Does anyone have any insight on why this may be happening?
Thanks for your help.