Bind9 reverse Delegation

I have a client that we are hosting that is using a full class C.  We are wanting to be able to delegate the class C to them for reverse lookups.   How do you set that up in bind?  I am familiar with standard reverse files, I have never had to setup a reverse delegation to another server though.

Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Assuming that you have authority for the Class B that the Class C is part of you can delegate it to them with:         86400  IN  NS  ns1.their-dom.tld.         86400  IN  NS  ns2.their-dom.tld.

in the reverse zone for the Class B. This is covered in detail in Chapter 9 of "DNS and BIND".
atebitAuthor Commented:
We have authority for a /21 (XXX.XXX.128.XXX - XXX.XXX.135.XXX)

Currently today I have a separate file for each of my class C's.  Is there a better way to do this?  

The Class C reverse zones have already been delegated to you and a zone can only be delegated once (ie. you can't "forward" the delegation on to them). You have two options:

1. contact the authority for the Class B that your Class C addresses fall under and get them to redelegate reverse DNS for the Class C you are giving to the client directly to the clients name servers.
2. Leave your server as authorative for the clients' Class C, but make that Class C zone a slave/secondary to a primary one that the client manages on their name server, that way your server will pull the data from theirs.

Reverse DNS is delegated along the octec boundaries and cannot be aggregated. Each Class C address block is a seperate domain. To compare, think about if you had two domains:

Is there any way of aggregating these two domains into a single file ? No, because they are totally seperate domains, as are each of your Class C address block domains. You can aggregate them for routing purposes, but there is no such aggregation for reverse DNS. (so your method for seperate files for each Class C is correct)



Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
atebitAuthor Commented:
Thanks for the reply.  I really like the slave idea.... That will help with some other issues :)  

It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Linux Networking

From novice to tech pro — start learning today.