Slave Server Notify

[Brad Beckenhauer]

Running Centos 5.5 with bind-9.3.6-4.P1.el5_4.2 (from the Centos repo) and I'm unable to get a slave server to retrieve the zone file from the master.

The master nameserver has a public ip address, the slave sits behind a firewall / NAT on a private ip address.

When I update a zone file on the master server, the slave receives a 'notify" (see log below) and (if I'm interpreting the log correctly) requests the zone file from the master nameserver, but ages out and logs the message "failed address not available".

In the named.conf file, I have the logging severity is set to "debug 9" for debugging purposes and I'm still not able to figure out why the zone will not transfer.

In the slaves named.conf file I have:
- logging severity is set to "debug 9"  (Temporary for debugging).
- allow-notify with the master nameservers ip address.
- transfer-source with the Public IP of the Private nameserver (the slave is behind a Nat/Firewall).
- allow-transfer with the ip address of the master nameserver.

Question: What is the "failed address" that bind is attempting to lookup so I can get the zone files to transfer?

Log file excerpt on the Slave server (IP's and domains obsecured):
19-May-2010 10:41:09.852 client: debug 3: client <master ns ip>#48605: notify
19-May-2010 10:41:09.852 general: debug 1: queue_soa_query: zone domain.com/IN: enter
19-May-2010 10:41:09.852 client: debug 3: client <master ns ip>#48605: send
19-May-2010 10:41:09.852 client: debug 3: client <master ns ip>#48605: sendto
19-May-2010 10:41:09.852 client: debug 3: client <master ns ip>#48605: senddone
19-May-2010 10:41:09.852 client: debug 3: client <master ns ip>#48605: next
19-May-2010 10:41:09.852 client: debug 3: client <master ns ip>#48605: endrequest
19-May-2010 10:41:09.852 client: debug 3: client @0x2aaaaacf5900: udprecv
19-May-2010 10:41:09.852 general: debug 1: soa_query: zone domain.com/IN: enter
19-May-2010 10:41:09.852 general: debug 3: dns_request_createvia
19-May-2010 10:41:09.852 general: debug 3: req_destroy: request 0x2aaaaac5f4d0
19-May-2010 10:41:09.852 general: debug 3: dns_request_createvia: failed address not available
19-May-2010 10:41:09.852 general: debug 1: soa_query: zone domain.com/IN: dns_request_createvia2() failed: address not available
19-May-2010 10:41:09.852 general: debug 1: cancel_refresh: zone domain.com/IN: enter