GForge needs its own domain. In example GForge configuration file, it's gforge.company.com. You should search for company.com in example GForge configuration file and replace it with your domain name.

Here some example configuration files for BIND are presented that can help you if you are not familiar with BIND but it's not meant to be complete. Don't ask BIND-related questions in GForge forums – consult documentation that come with your distribution and search in Internet. Distributions put files in different places and so there are no file locations here. The example configuration below is only quick start example and doesn't include reverse mapping.

New subdomain in gforge.company.com should be created. In company.com zone file, it may look like that:

gforge          IN      NS      ns.gforge.company.com.
ns.gforge       IN      A       1.2.3.4

New zone file for gforge.company.com may look like this:

$TTL    2d
@       IN      SOA     gforge.company.com. hostmaster.gforge.company.com. (
                              1         ; Serial
                         172800         ; Refresh
                            900         ; Update retry
                        2419200         ; Expire
                           3600 )       ; Negative Cache TTL
;
@               IN      NS      ns.gforge.company.com.
@               IN      A       1.2.3.4
ns              IN      A       1.2.3.4

download        IN      A       1.2.3.4
shell           IN      A       1.2.3.4
users           IN      A       1.2.3.4
lists           IN      A       1.2.3.4
cvs             IN      A       1.2.3.4
svn             IN      A       1.2.3.4
scm             IN      A       1.2.3.4
ldap            IN      A       1.2.3.4
jabber          IN      A       1.2.3.4

The new zone must be added in main BIND configuration file:

zone "gforge.company.com" {
        type master;
        file "/dist-specific/path/to/zone-file";
};

Of course, changes will take effect after reloading BIND.