Notify over Tcp?

Kevin Darcy kcd at
Wed Dec 1 03:23:11 UTC 2004

Mischa Diehm wrote:

>I read the following statement in rfc1996:
>   3.4. The transport protocol used for a NOTIFY transaction will be UDP
>   unless the master has reason to believe that TCP is necessary; for
>   example, if a firewall has been installed between master and slave,
>   and only TCP has been allowed; or, if the changed RR is too large to
>   fit in a UDP/DNS datagram.
>Now since this is exactly what I need so I wonder if it is possible to make
>the master believe that it is necessary to use TCP?
A brief perusal of the code indicates that BIND does not provide this 
functionality. Perhaps that could be requested as a feature. The only 
question then is: would it be a per-server option (which would be more 
consistent with the existing structure of named.conf), or should it be 
possible to just spontaneously declare whole address ranges "unreachable 
via UDP" (which might be more useful, since that's the way the firewall 
rules are typically written), or accept the protocol restriction in 
either form?

                        - Kevin

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