I have a client who are in process of moving some of their hosts/servers from the Data Center to their own Campus. They don't want to change the IP addresses and thinks that they can extend the VLANS over GRE/IPSEC tunnel. They are running a fiber between the Campus and the Data Center. I have never come a cross where you can extend VLANs over GRE/IPSEC tunnel. I know it is possible to extend VLANs over Layer II trunk as long as the switches at both ends are in a same VTP Domain.
Any feedback will be appreciated.