Quote:
| Needless to say, when we move web servers, there will be a very large DNS mess. |
If you have full access to the dns zones or you are the primary dns then there are some ways to minimise problems (SOA records).
Quote:
| In an effort to make the transition as smooth as possible, is there a way to redirect traffic arriving at the old site to the new site using the firewalls so we can proceed more cautiously than an all-at-once deal? |
I don't know the volume, but maybe it is possible to work with mapped service to minimise the effect
old site: ip1 -> http_mapped_ip1 (80,new_ip(via vpn),80)
also I can think about a dedicated balancer behind the old FW that do the redirect (OpenBSD comes in my mind very intuitive and fast to setup)