Zone refresh fails due to cached server. how to use different port

[Michael A. Hess]

Greetings,

My DNS is located behind a firewall. Specifically a Dlink 614+ router.
It works find as a DNS and as a Master but there is a problem as a
slave. My DNS acts as a slave for several domains. However Zone
transfers fail.

The reason is that the Dlink rounter has a caching server embedded
that traps any DNS requests attempting to go out of the network. This
only applies to UDP requests. It doesn't matter if you specifically
ask to retrieve the information from a DNS outside of your network or
not. The router intercepts any DNS request an processes it before
actually recursing the request out to the DNS server you specify. The
result is that my router always responds to any of my Zone transfer
requests which isn't authoritative so my zone updates fail.

Question:

I have been reading the Bind 9 docs trying to understand if it is
possible to get the DNS to do a refresh request on a different port
other then 53. I still need the server to listen and respond on 53 I
just want the zone transfers done on a different port. If that is not
possible can the zone transfer be setup to be done over TCP instead of
UDP? TCP requests do respond with a flag of aa since the router is
only trapping UPD 53 requests.

Thanks for any help any can give me on this one.