[Glastonbury] DHCP and fixed IP addresses

[Rick Fitzsimmons]

Hi again,

On Wednesday evening, a couple of people were asking about DHCP 
operation, and specifically setting up fixed address leases. To 
summarise, you can specify fixed settings for individual hosts by 
specifying their MAC addresses in the /etc/dhcpd.conf file. This means 
that all your IP address allocation can be set in one place, including 
fixed items like servers etc. This also allows control of dns addresses, 
default route (gateway) etc, although these are normally done per 
sub-net rather than per-host.
Add to this a dns proxy that uses the server's own resolver, and you can 
set up a single hosts file that is effectively used throughout the 
network. Then all IP address administration is in one place (i.e. all 
eggs in one basket).
(I don't claim to be real expert on this, but I've made it work. Feel 
free to correct / amend / add to what I've said!)

<Asbestos suit>
I generally use webmin to administer all this sort of stuff, as I can 
never remember the syntax. Anyone care to start a heated exchange of 
views on webmin? ;-)
</Asbestos suit>

And finally - if you're using an appliance like an ADSL router or 
wireless AP to do DNS, the "advanced" stuff might not be in the 
browser-driven configuration options. On my Draytek Vigor router, I have 
to telnet in to set up dhcp leases and the like. Check the 
manufacturer's support pages (good luck).

Cheers,
Rick.