Can I have your input on drafting up some instructinos to pass to an webhost on what they must do to make me responsible for the reverse DNS of IP's assigned to me.

I have little experience of how reverse dns works in the internet world, I know what happens locally, but im unsure of what constraints I am under when people query there DNS and the root servers tell them where to go, I assume its for a large IP block or something, one DNS server for that block, in the root hints.

So how to get can I be responsible for reverse dns on a few ips in the internet world ?

You should ask your provider to see if they allow this. All then need to do is create CNAME PTR records and point each IP address to your name server.

Hope that helps!

Im 99.999% sure they will do it for me ;)

Anyhows, this CNAME PTR, thats a new one for me, is it just like normal CNAME ?

Would the entry look like this or something ?

138 IN CNAME PTR admin.mghost.net.

admin.mghost.net being the dns name of the nameserver responsible.

You need them subdelegate the reverse dns to your own nameservers.

There are plenty of resources for fragmenting reverse zones, and they are usually in the form of 0-xxx.xxx.xxx.xxx.in-addr.arpa rather than xxx.xxx.xxx.in-addr.arpa

There is not enough room here to explain, so read up and learn.

If youd care to share some links, that could prove to be "useful".

often times it's just easier to get your server provider to modify the records for you, depending on setup granted as they have everything in one big fat file for each zone, and can just dump reverse information quickly. Personally we've got it half setup to tie into our customer information database (we get ip justification, it goes into the database, the hostname submitted on the justification is saved in the ip address table, then the reverse dns zones are generated from this table, so anything thats been properly jusitified and is in our database will automatically be setup for reverse with the click of a mouse :)).

Some companies don't know how to do this. One of my friends has a class-C through cognet or qwest and their support staff gets lost when I ask them to give our nameserver authoratative access over the ip's. :(

What they have to do most likely is stated in RFC2317 (http://www.faqs.org/rfcs/rfc2317.html)

How many Ip's you looking at ?
If not many.. I would suggest that they put in their reverse DNS something like this:

14 IN NS YOURDNS.SERVER.COM

If it's a whole class /24 or bigger... then I would suggest the slave the zone and do a pull from your nameserver. That would take place normally in the named.conf file:

zone "xxx.xxx.xxx.in-addr.arpa" {
type slave;
file "xxx.xxx.xxx.in-addr.arpa";
masters { yyy.yyy.yyy.yyy;};
};

xxx represents the ip numbers for your reverse
yyy represents the ip number of your nameserver.

There are other options...I do believe...but this is probably one of the more simpler forms.