[Dnsmasq-discuss] When Client is set to DHCP
Tue, 30 Nov 2004 07:58:19 +0000
Ross Williams wrote:
> 1. Configure on the client the DHCP 'host-name' option to whatever
> hostname you want that client to be known as in dnsmasq. Some client
> software seems to interchangeably refer to the host-name option as the
> client ID option, although the two are different. The dnsmasq man page
> refers to both the host-name option and the client-id option, and I
> believe that they are handled differently. Simon or someone else,
> however, would have to answer that question.
Think of client-ids as a stable indentifier for the system: what most
people use the MAC address for. The idea is that the client-id can be
derived from something like a motherboard serial number or OS install,
and then a faulty network interface could be swapped out without
disturbing the configuration of the DHCP server. In practice most DHCP
clients either don't send a client-id (in which case the MAC address is
used instead) or they send the MAC address as the client-id, so the
practical effect is zero.
In any case host-name is not equal to client-id. A machine could change
its host name and still be given the same IP by DHCP. If it changed
client-id it would be seen as a new machine and given a new IP address.