Q. There is a secondary address configured on a TCPware system that is also running as a DNS nameserver. Some DNS clients can not resolve names when they are configured to use the secondary address as their DNS nameserver. Why?

A. If a DNS client checks to ensure that the response it gets from a DNS query comes from the same address that the query was sent to, then it will not be able to use the secondary address as its nameserver. This is due to the way secondary addresses work on TCPware.

There are two possible solutions:

1. If the client can be configured to accept responses from addresses other than the one the query was sent to, the problem will be eliminated.

2. Starting with TCPware v5.3-3, pseudo devices can be used instead of secondary addresses. DNS queries sent to a name server running on a pseudo device will be answered from the address they were sent to and will correct this problem.