How to get resolve fake domains, aka split dns, with Ubuntu 8.04

[strafford]

Thanks to soxfan and uxbod I was finally able to get a split dns - to resolve a fake domain - running on my install of Ubuntu 8.04 Server Ed. (mine is 64 bit). There are how-tos and other posts on this but they did not contain all the info I needed to get this running.

Be sure to do this BEFORE you install Zimbra. My machine name is mailserv and the sub-domain mailserv.mydomain.com does not actually exist. Local IP address is 192.168.7.101.


1.Install Ubuntu Server Ed. (no GUI, no extras/add-ons). Basically, you can take all the defaults (just make sure your networking is setup correctly).

2.Install openssh-server - optional but allows remote admin - and bind9 (using apt-get).

3.Setup /etc/hosts file as follows (where mailserv is the name of the machine and 192.168.7.101 is the local/internal IP address of the machine):

127.0.0.1       localhost.localdomain localhost
192.168.7.101   mailserv.mydomain.com mailserv

4.Setup /etc/resolv.conf as follows (w/ local IP address):

search mydomain.com
nameserver 192.168.7.101

5.Setup /etc/bind/named.conf.options:

options {
        auth-nxdomain no;    # conform to RFC1035
	query-source address * port 53;
      	directory "/var/named";
      	dump-file "/var/named/data/cache_dump.db";
	        	statistics-file "/var/named/data/named_stats.txt";
        		forwarders { 24.226.1.93; 24.226.10.193; };
};
include "/etc/bind/rndc.key";
zone "mydomain.com" {
        type master;
        file "/var/named/db.mydomain.com";
};

Note. You will probably have to add the /var/named and /var/named/data directories. Also, the forwarders are the IPs of your actual DNS servers, usually assigned by your ISP

6.Setup a new file /var/named/db.mydomain.com:

		;
		; BIND data file for mydomain.com
		;
		$TTL    604800
		@       IN      SOA     mydomain.com. admin.mydomain.com. (
                    		     070728         ; Serial
                         		604800         ; Refresh
		                          86400         ; Retry
                        		2419200         ; Expire
		                         604800 )       ; Negative Cache TTL
		;
		@       IN      NS      192.168.7.101
		        IN      A       192.168.7.101
		        IN      MX      10 mailserv
		mailserv        IN      A       192.168.7.101

Note: You MUST update/increment the serial number in this file each time you change it. Otherwise the changes will not take. Also, on the IN SOA line, the second entry is your domain's administrator email address, but using a '.' in place of the '@' symbol.

7.Fix apparmor (there is a bug) by changing the following line in /etc/apparmor.d/usr.bin/named:

/proc/net/if_inet6 r,

to:

/proc/**/net/if_inet6 r,

8.Also set apparmor to only complain about bind:

sudo aa-complain /usr/sbin/named

9.Reboot. Check that all is working by issuing the command nslookup on your “domain” and you should get a response somewhat similar to:

user@mailserv:~$ nslookup mailserv.mydomain.com
		Server:         192.168.7.101
		Address:        192.168.7.101#53

		Name:   mailserv.mydomain.com
		Address: 192.168.7.101

[jigskep]

Hi,

First of all, thank you for the detailed information. I tried your method but it does not seem to be working.. After following all the steps when I do nslookup, it sill shows some public ip rather than my local ip. Am I missing something ???

I know its an old post but hope to see some reply

Thanks.

[phoenix]

Originally Posted by jigskep

First of all, thank you for the detailed information. I tried your method but it does not seem to be working.. After following all the steps when I do nslookup, it sill shows some public ip rather than my local ip. Am I missing something ???

This subject has been covered many times in the forums, there's even a wiki article on Split DNS - read that article for details on what's needed (or search the forums) and confirm the settings by running all the commands in the 'Verify....' section of that article.

[strafford]

Originally Posted by jigskep

Hi,

First of all, thank you for the detailed information. I tried your method but it does not seem to be working.. After following all the steps when I do nslookup, it sill shows some public ip rather than my local ip. Am I missing something ???

I know its an old post but hope to see some reply

Thanks.

All I can say at this point is double and triple-check your setup/settings files. That is where I found most of the problems were.