Zone Transfer Authorization

Our Secondary DNS feature allows a zone to be transferred from one or more master name servers to our Route name servers. This initial zone transfer, along with subsequent synchronizations, requires that our Route transfer system be allowed access to the master name servers that host the primary zone.

Our Route transfer system communicates with master name servers over port 53 (UDP/TCP) using the following IP blocks:

IP blocks (IPv4):

IP blocks (IPv6):