connection between master and slave DNS server's

[John]

Hi all,

We have HP-Unix DNS BIND 8.2.5 in all DNS servers.
Last time we have put FireWall between the DNS's, we use port 53. The
slave DNS we have activated the next line in the option:
                         query-source address 194.229.188.24 port 53;
But not in the master DNS!!!

Now the problem is comming.

In our slave DNS under                 /var/adm/syslog/syslog.log.
I found there continuous error messages like: "Err/To getting
serial:........."
It looks like the slave DNS can not get the serial from the master.
But when I change the serial to a newer number in the master, the master
can transfer the serial to the slave DNS...no problem.
So my question is Master DNS can transfer serial number to slave without
problem, but when the slave DNS send a request to the master it can not
get the serial from the master?? Why??
Do I need to activate port 53 on the master DNS??

Pleas let me know.

Regards,

John Ho