[TriLUG] Dynamic DNS

[Joseph Tate]

Tayfun Teksoy wrote:
> I am using RedHat 9.0.
> Is there a way to set network properties so the dynamic DNS updates are 
> possible.
> Recently DNS settings for Road Runner changed and I had problems sending 
> mail.
> Each time the DNSserver IP address changes I have to manually cahnge the
> Network settings.
> 
> Thanks
> 

I don't know that I understood you, or if you want what Jon suggested.

If you want to update DNS when your own IP address changes:
Depends on how integrated you want it to be.  For me a simple cron job 
that runs once every five or ten minutes checking the external IP to see 
if it's changed and then sending the DNS update was sufficient.  I 
believe there's a way to move that into the dhcpd-client, but that's 
left as an exercise for the reader.

If you mean when the IP addresses for RR's DNS servers change, usually 
DHCP takes care of that.  May need to reboot the cable modem and or 
router, but shouldn't need to.  Then your router (if there is one) will 
hand out the new DNS settings when the lease is renewed.  You do know 
how to manually renew your DHCP lease don't you?  However, if you're 
using a static IP behind a commodity internet router, you'll need to do 
much script-fu-lery to get it to work.  Running caching name server is 
much simpler.

My personal setup is as follows:
I have the cable modem plugged into a Belkin 54g wireless router/switch. 
  It is bridged to a Belkin 54g WAP, and then connected to a 8 port 
switch.  On the router I have DHCP and DNS services turned off.  I run 
these from my Linux server (where I have static entries for my main 
machines).  The DNS is maintained internally so that within my network 
if you type www.dragonstrider.com, it'll go to 10.2.2.2 instead of what 
ya'll resolve that address to.  I would have left these services on the 
router, but my #$%*& router doesn't have the granularity of settings 
that would be necessary to perform the same function.  Perhaps when the 
warrantee expires I'll try using one of the modified Linksys firmwares 
on the box.

Joseph