Hello all. In a couple of months I will be replacing my company's core firewalls/routers at our datacenter location. This pair of firewalls is currently what handles intersubnet routing, NATing, and general communication with the internet. Currently, our core switches are not configured to handle the routing (this is being addressed but not for a little while) so since Exchange is on a different VLAN than AD, there is going to be an abrupt halt to all communication between my Exchange 2013 DAG (and CAS) servers and the previously mentioned services.
Is there any harm in just yanking the firewalls out and letting everything go dark for a bit, or is it strongly recommended that I put my servers into maintenance mode while I do the cutover?
As a note of interest, our DAG is not stretched between sites, it is a simple two node DAG with both hosts (and the witness server) on the same subnet with a third mailbox server for our archive mailboxes.
Thanks!