[c-nsp] DHCP server suited for option 82

[Miquel van Smoorenburg]

On Mon, 2009-04-27 at 23:04 +0100, Simon Lockhart wrote:
> On Mon Apr 27, 2009 at 02:08:59PM -0700, Charles Wyble wrote:
> > http://www.thtech.net/article/10 for ISC example
> 
> That appears to be the canonical example that's trotted out everytime
> Option 82 is mentioned. Fine if all you want to do is log the Option 82
> information, but less than useful if you want to do anything intelligent 
> based on it.

Yup, it's hard to find a working config sample.

This is the way to do it-

# dhcpd.conf
#
stash-agent-options true;

subnet 192.168.1.0 netmask 255.255.255.0 {

        option broadcast-address 192.168.1.255;
        option routers 192.168.1.1;
        option subnet-mask 255.255.255.0;

        # Match on circuit-id.
        class "id-192.168.1.10" {
          match if option agent.circuit-id = "ATM 2/1/0.3";
        }
        pool {
          allow members of "id-192.168.1.10";
          range 192.168.1.10;
        }

	# ... more here ...
}

This scales up to about 5000 entries, then it gets slow. I patched ISC
DHCPD to scale beyond that, perhaps I should publish that patch
somewhere.

Mike.