Linux – DNS propagation delay or bad configuration

Looking at the IP addresses in your resolv.conf I get the feeling that your BIND server is on 192.168.1.52. As far as I can tell, you can't specify in resolv.conf something like "for these domains, use this name server". Basically, your BIND server will never be queried. As you can see in your dig lookup (which is incorrect, it is asking for a reverse DNS entry), it tries 80.58.0.33, which I assume is your provider's DNS server.

You already set up BIND as caching nameserver by using the 'forwarders' option, so what you need to do is have only 192.168.1.52 in the client PCs as nameserver.

To see if your BIND is configured correctly, try this:

dig example.test @192.168.1.52

Your origin for the zone is . per your configuration. You are creating records for ns1. and ns2. instead of ns1.example.com. and ns2.example.com. Since ns1.example.com and ns2.example.com aren't defined, they are matched by the wildcard.

EDIT: here's an edit of your config and zone:

zone "example.com." {
        type master;
        file "ext.zone";
};

ext.zone:

$TTL    3600
@       IN      SOA     ns1 root (
                              1         ; Serial
                         3600         ; Refresh
                          300         ; Retry
                         3600         ; Expire
                         300 )        ; Negative Cache TTL


        IN      NS      ns1
        IN      NS      ns2
        IN      A       192.0.2.6


ns1     IN      A       192.0.2.4
ns2     IN      A       192.0.2.5

*      IN      A       192.0.2.6

Everything in the zone is relative to the zone name in the named configuration, so adding a second zone just points to the same file:

zone "example.net." {
    type master;
    file "ext.zone";
};