Bind DHCP to a specific ip

[sthaug at nethelp.no]

> >No, it doesn't go in the dhcpd config file, it goes on the command 
> >line that invokes dhcpd. There will almost certainly be a system 
> >specific config file where the list of interfaces can be specified. 
> >Failing that, you have to edit the script that starts dhcpd.
> You guys were right, there is a file to define the interface. On SLES10 SP3 it is found in /etc/sysconfig/dhcpd. It was already defined in that file but still shows as 0.0.0.0:67 in netstat. Is that the way it was designed?
> 
> I can get netstat to show the ip:67 by entering local-address "ipaddress" in the dhcpd.conf file.

Whether you need to bind to a specific IP address or not depends on
what you want to achieve.

My situation is that I for various reasons need to run several dhcpd
processes, listening on different addresses, *and* all my clients are
behind DHCP relay agents. In this situation:

- The normal broadcast handling that dhcpd performs (being able to
receive/process broadcast packets) is not needed - *all* DHCP traffic
is unicast as seen from the server.

- It is necessary to have dhcpd listen to a specific IP address (not
INADDR_ANY) port 67, in order to run several dhcpd processes.

YMMV.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no