Why do I get lots of 407 and 408 Event IDs in my DNS event log?

If you also have NAT installed on the same server that hosts the DNS server, you will get these errors. NAT has a DNS Proxy setting that enables DHCP clients to direct DNS queries to the NAT server. The client DNS queries are then forwarded to the NAT server's configured DNS server. The DNS Proxy and the DNS Server service cannot coexist on the same host, if the host is using the same interface and IP address with the default settings.

To workaround this issue, use one of the following three methods:

1. Install NAT and DNS on different servers.

2. Use the DHCP server Service in NAT, NOT the DHCP Allocator and DNS Proxy.

3. Set the DNS Server so it doesn't listen on the IP address of the NAT private interface:

   1. In the DNS MMC snap-in, right click the DNS server and press Properties.

   2. In the Listen on section of the Interfaces tab, select the Only the following IP addresses check box.

   3. Select the IP address that you do NOT want the DNS server to listen on, and press Remove. DNS will NOT respond to queries that are directed to this removed address.

   4. Press OK and close the snap-in.