Sometimes it is handy to know what version of BIND someone is using on a site, especially when the people involved have no idea what BIND is or what you are talking about when you ask them.
Quick and easy way with the BSD/*nix version of nslookup:
“nslookup -q=txt -class=CHAOS version.bind. 0 dns.roflcopter.com"
Server: dns.roflcopter.com
Address: 127.0.0.1#53
version.bind text = "9.2.4rc6"
So, if 'dns.roflcopter.com' actually existed, they are running 9.2.4.rc6.
On any DNS server that I have running BIND, I tend to fake the version returned, so this isn't always accurate. You can accomplish this by setting 'version' within the options section of named.conf
For instance:
options {
directory "/var/named";
version "Go away"
};
Why? I don't like users knowing the version numbers of software I am running. Worms and script kiddies love looking in search engines/etc for versions of software that can be easily exploited. For instance if your system advertises that it is using "Whizzbang 1.0.1" and a new exploit comes out for any version of 'Whizzbang' earlier than 1.0.2, you will most likely have people trying to get in. Of course most scripts will just try a brute-force attack, and if you are vulnerable, you are already hosed.
A great resource for securing BIND by Rob Thomas (not singer), is located here:
http://www.cymru.com/Documents/secure-bind-template.html
