i having a customer which host their own domain name, there are Nameserver 1 and nameserver 2,aka NS1 and NS2, and they hosted thier own exchange server as well.
Right now, they having a DR site, which have passive Exchange server, which just replicate the database.
If they plan to setup a new NS3 server at DR site, what could be the advise? should i replicate it from primary DNS or i should setup the standalone NS3.
NS1 = ISP A, NS2=ISP B, NS3 =ISP C