Notify in Bind 9

[Steven]

Hello all I have a silly question about Bind 9 that I figured you
guru's would be able to answer. I am trying to find out what port bind
sends notify request to. Does it send over UDP or TCP 53?? The reason
I ask is because I have a hidden master server that sends notifies to
my three slave servers, but it is always not getting to one server.
Yet that one server can be seen and hit from the master so at this
point I am thinking it's a network issue, but before I go and have my
neteng group look into this I would like to have a better answer to
give them as to where the traffic is going.


Thanks All
-Stephen