Resolving to a dynamic IP address

[Kevin Darcy]

Chris Harshman wrote:

> I have a dynamic IP address on my DSL feed at home, and a Linux box
> setup on it.  I had a decent little setup going with a simple redirect
> from a box I run here (http://dominion.sonypictures.com/redirect), but I
> decided to get fancy and see if I couldn't get a little DNS action
> going, much like tzo.com or dynip.com provides, but for free.  =)  This
> is just a mucking-around-would-be-kinda-cool-if-I-could-pull-it-off kind
> of stunt, nothing mission critical.  (No one is *that* interested in my
> life.  I think I've had five hits in the past month.  =)  But now that
> I'm this close...
>
> I have a server at school named ebhon (which is also ip aliased as
> paradigm).  I set up DNS on that box, and built records for it that can
> be parsed with sed and updated with my IP address, when it changes.  I
> have a cron job running on my home Linux box that runs a PHP script on
> ebhon that updates the DNS records and restarts ndc whenever my home IP
> address changes.   (If/when I get this working, I'll pull all the steps
> together into a "HOWTO" so that others can benefit from my loss of
> hair.)
>
> I can do nslookup on ebhon talking to localhost and it resolves just
> fine, but I can't get off-site lookups to work, or local lookups, when I
> specify ebhon as the DNS server.  Of course, reverse DNS maps
> differently, as PacBell owns my IP addresses:
>
> ebhon:/etc# nslookup divus.org
> Server:  localhost
> Address:  127.0.0.1
>
> Name:    divus.org
> Address:  63.205.137.95

Is this not the correct response?

> ebhon:/etc# nslookup divus.org 192.251.xxx.yyy
> *** Can't find server name for address 192.251.xxx.yyy: Server failed
> *** Default servers are not available

Your immediate problem is that you're using nslookup instead of a
reasonable lookup tool like dig. nslookup is croaking because it can't do a
reverse lookup of 192.251.xxx.yyy. Since it's not getting past that error,
there's no telling whether your DNS machinations are working or not.

By the way, are you using true Dynamic Update for this, or just munging the
zone file and reloading the
server?
- Kevin