DNS and DHCP question

[Kevin Darcy]

Kevin White wrote:

> Hi everyone,
>
>         I hope someone can answer this question, details would be nice, but a
> simple yes or no would suffice, and maybe a chapter # in oreily's dns
> bind book ;)
>
> What we've got is a server running a static IP and another stuck with
> dynaic ip for the time being.  What we'd like to do is have all our
> workstations see the static server for DNS and somehow have the dynamic
> server tell the static server what IP it's currently at.   We've got no
> problem if we use the host file and do it manually, but sometimes the IP
> changes when we're not around, and that could fubar the software thats
> running at the dynamic site.
>
> Any clues?  or do we just need to write a script ;)
> That is our next plan, If anybody already has a script that will take
> ipconfig output and grab the eth0 ip and update the host file on the
> remote PC ;)
>
> BTW,  Both PC's are running RH7 with whatever version of bind comes with
> those. ;)

You could have a script run "nsupdate" whenever the server's address changes, to
Dynamically Update the nameserver with the new IP address. Unless you completely
trust the *entire* range of dynamic addresses, you should use TSIG to
authenticate the Dynamic Updates. See the man page for "nsupdate" and
http://www.nominum.com/resources/faqs/bind-faq.html#tsig regarding the creation
and use of TSIG keys.

If RH7 doesn't come with "nsupdate", you may have to compile that program
yourself from the BIND sources.


- Kevin