controlling DHCP

[david at thekramers.net (David Kramer)]

James R. Van Zandt wrote:
> David Rosenstrauch <darose at darose.net> wrote:
>>   ... a better solution to the problem is this:  run an 
>>   internal DNS server on your LAN, and your problem is solved.
> 
> Right.  Simple job for a Linux box, though I've been trying to leave
> mine off to save power & wear and tear.  However, my router (Linksys
> WRT54GS, firmware v2.07.1) is *already* a Linux box.  I guess I have
> to install third party firmware to get DNS running there.  Anybody
> have experience with this?

I'm sorry if I missed anything from not having watched this thread
closely enough, but your WRT54GS already serves DNS internally.  The
initial problem seemed to be the way it was configured (the expiration,
IIRC).  Why is this insufficient?

> By the way, the other reason to leave local machines DHCP rather than
> static, is that when the cable company moves their DNS servers, your
> machines get reconfigured automatically.

Again, apologies if I miss anything, but why would you need to change
internal IP addresses just because your external IP address changed?  If
the internal addresses are 192.168.1.0/24, and my external address
changes from 66.92.68.235 to 66.92.68.221, the router adjusts
accordingly and NATs everything to the new address outbound, but the
internal adresses need not change at all.  Different subnet, and nobody
on the other side of the router even knows they exist.