wiki:split DNS (domain names)

[rosch]

Hi all,

I am setting up a zimbra test environment with split DNS.
Following the wiki article where the fully-qualified server name is server.example.com.
Now in the db.server.example.com zone file there is an MX entry for mail.yourdomain.com.
Is "yourdomain.com" the same than "example.com"?
Can it be the same at all?

ps: this might be obvious but it isn't to me..

[blackpuma]

Originally Posted by rosch

Is "yourdomain.com" the same than "example.com"?

Yes. What we're trying to do is intercept DNS queries for the mail server and return the local IP address (behind the firewall), rather than the address outside of the firewall. This includes the mail (MX) record.

For example, if I were setting up split DNS for a Zimbra server behind the ACME Corporations' firewall:

server (host) name: mail.acme.com
IP address: 192.168.1.2
DNS: 1.2.3.4 and 5.6.7.8

the configuration file would have:

// Default named.conf generated by install of bind-9.2.4-2
options {
       directory "/var/named";
       dump-file "/var/named/data/cache_dump.db";
       statistics-file "/var/named/data/named_stats.txt";
       forwarders { 1.2.3.4 ; 5.6.7.8 ; };
};
include "/etc/rndc.key";
// We are the master server for server.example.com
zone "mail.acme.com" {
    type master;
    file "db.mail.acme.com";
};

and the file /etc/named/chroot/var/named/db.mail.acme.com would have:

@       IN      SOA     mail.acme.com. admin.mail.acme.com. (
                               10118      ; Serial
                               43200      ; Refresh
                               3600       ; Retry
                               3600000    ; Expire
                               2592000 )  ; Minimum

               IN      NS      192.168.1.2
               IN      A       192.168.1.2
               IN      MX      10 mail.acme.com.

[rosch]

Originally Posted by blackpuma

Yes. What we're trying to do is intercept DNS queries for the mail server and return the local IP address (behind the firewall), rather than the address outside of the firewall. This includes the mail (MX) record.

Ok, so in the wiki I think one should decide to use only one of both to reduce confusion, either yourdomain.com or example.com.

[blackpuma]

Yes, that should be tweaked.