zone transfer stopped and Bind stopped responding

[Chris Henderson]

My slave is not updating my domain.com from my primary for the last
one week and not responding to any DNS queries. And it's now giving me
error:

[ID 873575 daemon.warning] zone 'domain.com/ IN' expired
[ID 866136 daemon.error] transfer of 'domain.com/IN' from <IP of
Primary#53>  failed to connect: timed out

This started happening around about a week ago when I made a silly
change to the domain.com file on the primary - I have now commented
out the change on the primary, updated the date and HUP'd the pid for
named on both the primary and secondary but I am still get this error.
I am not sure of both this is coincidental.

nmap shows my secondary's port 53 is open but if I use my secondary as
my resolver I get SERVFAIL error from nslookup - it's not resolving
host names although it looks like it's running. Nmap also shows my
primary's port 53 is filtered but when I do nslookup I get reply back
and tcpdump shows it's querying port 53.

Here's the named.conf snippet for domain.com from primary -

view "external" {

match-clients {203.75.23.0/24; !127.0.0.1;  any; };
zone "domain.com" {
        type master;
        allow-update { none; };
        allow-transfer { any; };
        forwarders { };
        file "external/domain.com";
  };

Here's the named.conf snippet from secondary for domain.com

zone "domain.com" {
        type slave;
        file "bak/domain.com";
        allow-transfer { any; };
        forwarders { };
        masters {
                <master's IP>;
        };
};

The slave is doing zone transfers from other masters on other domains
but not updating anything from this master server.

Any way to force zone transfer or copy the zone file from somewhere else?

Thanks for any help.