I am working a project with FiberNet. It involves 3 x geographic locations. Each location has dual core switches (4506+SUP4 or Cat3750 stacked switch)and each of the switch has a WAN link connecting to other node. The topology is attached.
In Location C, I found that I cannot discover remote end by CDP via "show cdp nei". When I raise it out to telco, they said Cisco CDP is transmitted over native VLAN. Because the WAN link is VLAN tagged (allow 504 to Location A and 502 to Location B only). Can anybody help it?