dhcpd and multiple subnets

[vdubjunkie]

All,

Hi, I used to post in bsdforums.org, but dropped off the map for a bit. Recently ice storms took all my hardware down hard, and long story short, I took the opportunity to reload OBSD. I thought I remembered having dhcpd serve two different interfaces with two totally different subnets, but I cannot for the life of me figure out how to make this configuration work. Was I just mistaken, and my AP was doing the dhcp previously? I was sure it wasn't.

Anyway, my config is this.

xl1 - wired net - 10.100.0.0/24
xl2 - wireless net - 172.16.0.0/24

If anybody had a sample config or even a push in the right direction it would be much appreciated.

[DutchDaemon]

I've never done a 'dual dhcpd' setup, but I'd assume something like this could work:

dhcpd_ifaces="xl1 xl2"

In dhcpd.conf:

subnet 10.100.0.0 netmask 255.255.255.0 {
  range [...];
  option [...];
  option [...];
  default-lease-time [...];
}

subnet 172.16.0.0 netmask 255.255.255.0 {
  range [...];
  option [...];
  option [...];
  default-lease-time [...];
}

In other words: declare all options in separate subnet containers. This is all under the assumption that dhcpd will know which interface a dhcp request is coming in on and which subnet to associate with that request.

[BSDfan666]

You really need to stop giving FreeBSD advice in the OpenBSD sections DutchDaemon..

To specify interfaces dhcpd(8) should listen on, add change dhcpd_flags="" to something like dhcpd_flags="xl1 xl2" in /etc/rc.conf.local.

See: http://www.openbsd.org/faq/faq6.html#DHCPserver

Perhaps something like this will work?

shared-network WIRED {
	option domain-name-servers 10.100.0.1;
	subnet 10.100.0.0 netmask 255.255.255.0 {
		option routers 10.100.0.1;
		range 10.100.0.2 110.100.0.254;
	}
}

shared-network WIRELESS {
	option domain-name-servers 172.16.0.1;
	subnet 172.16.0.0 netmask 255.255.255.0 {
		option routers 172.16.0.1;
		range 172.16.0.2 172.16.0.254;
	}
}

This configuration assumes xl1 and xl2 are configured to have the addresses 10.100.0.1 and 172.16.0.1 respectively, and that a DNS server.. like named(8).. is listening on both interfaces.

Note; I'm not aware of any wireless 3Com/xl(4) devices.. so that was probably a typo.

[vdubjunkie]

Thanks a lot for the reply BSDfan666. I'll try implementing this tonight.

[vdubjunkie]

oh. for the record, I did actually do both search google and FAQs. Not sure how I would have missed it in either place, but oh well. I also already had the rc.conf.local issue sorted out, but had my two networks listed under the same "shared-network". When I get home I'll be able to test it.

[BSDfan666]

Apologies, that is my signature.. it is not directed at you personally.

Sorry for the confusion.