I have been tasked with our upgrade from Exchange 2010 to 2013. In planning the migration, I was also asked to make some topology changes and I am unsure of the best way to accomplish this during the migration.
Here is our current setup: Site A is internet facing with edge server in DMZ, CAS/MBX/HT on LAN hosting OWA. Site B is across a WAN link and has a CAS/MBX/HT server.
In the process of migrating from E2010 to E2013, I was asked to make the Site B location the new internet facing site and also move all mailboxes to that site instead of having the multiple CAS/MBX/HT set that we currently have. I understand that E2013 does not have the edge role, so I need to decide how best to take on this migration.
1) Do I first change the E2010 setup to make Site B the internet facing site and then perform the migration?
2) Or, would it be better to install the new E2013 server at Site B and move the mailboxes to it while coexisting? Then make Site B internet facing afterwards. I read that the internet facing site should be migrated first, so this is a concern.
Thanks for any suggestions/input.