TM internetworking products incorporate a DNS caching proxy that can serve local hostnames and forward
DNS queries to different upstream servers based upon the domain part of the query.  This provides tremendous flexibility for remote offices that have VPN connections to a main office.  For example, a remote office may have a few locally defined hostnames, forward all queries for the "inside.acme.com" domain to DNS servers at the main office, and forward all other traffic to Internet domain servers.