Q. Why can some DNS clients not resolve names when they are configured to use the secondary address as their nameserver?

A. If your DNS client checks to ensure that the response it gets to a DNS query comes from the same address that the query was sent to, then they will not be able to use the secondary address as their nameserver. This is due to the way secondary addresses work on TCPware. If the client can be configured to accept responses from addresses other than the one the query was sent to, this will workaround the problem. In TCPware v5.3-3 and later, you can configure pseudo devices instead of using secondary addresses. DNS queries sent to a name server running on pseudo devices will get answered from the address they were sent to and will correct the problem.