I am not sure if this belongs in openvpn or IPSEC so bear with me please. I would like to have a DR site that extends on the IP scheme in my current network to the point where if my dhcp server on the local site fails, the peer node on the DR site would take over.
Would any type of VPN config provide this type of functionality?
OpenVPN may do it.
Discaimer: I've NEVER architected a network with a need for a site-to-site VPN bridge. Site-to-site bridge, sure, using L2 switches. VPN, absolutely, but they have always been routed.
I had initially started to write an "It can't be done" reply, but started reading openVPN's doc's and howtos. OpenVPN supports a bridged VPN config, but I'm not clear if it works with site-to-site, or only in a road warrior scenario..
Regardless, a site-to-site bridged VPN would be a huge waste of network and processor bandwidth.