[PATCH] Add OPTION_DOMAIN_NAME to DHCP request parameter list

[vegardw]

The following patch adds OPTION_DOMAIN_NAME to the DHCP request parameter list. The DHCP server on my linux box (dhcp3-server) doesn't send the domain name option unless it's requested by the client.

[stippi]

Can this patch have any negative side effects? I am just wondering because it's called "required flags" in the code, but the domain name is perhaps not strictly required. Please excuse my ignorance with regards to networking, but what is the domain name good for?

[vegardw]

I'm pretty new to DHCP myself, only started looking at it a couple of days ago. But it shouldn't have any side effects.

According to the RFC the server must supply any parameters in the list it can provide, and omit any parameters it cannot provide. So a server that isn't configured with a domain name should simply return the other options in the list, and omit domain name. So it shouldn't have any negative side effects. The dhcp-client in linux requests several options that the dhcp server doesn't supply, and the only thing that happens is that those aren't sent from the server.

So it's more a case of the variable name being a bit misleading in my opinion.

The domain name is the local domain / the first search domain that the resolver tries when looking up a name. On my local network at home I use the domain intra.vegardw.com, and for example my linux box is called debian1.intra.vegardw.com. With the domain field set to intra.vegardw.com I can just do 'ping debian1' to ping the server instead of 'ping debian1.intra.vegardw.com'. So mostly it is for being able to address the hosts in the local domain by using just the hostname instead of the fqdn.

[axeld]

Applied in hrev35956, thanks!