host-identifier and option 82

[Ed Ravin]

On Sat, Jan 28, 2012 at 01:19:40PM +0100, Christian Kratzer wrote:
...
> the hack to use a separate class and pool for each switchport is no
> longer necessary sind isc dhcp has backported host-identifier from
> dhcpv6. Sadly the web is full of howtos how to set this up with classes
> and ranges.

And even more sadly, the ISC documentation in of dhcp-4.2.3 doesn't seem
to mention it.  For example, here's a clip from the dhcpd.conf man page,
which I read through a dozen times while working on that project:

**   host-identifier option option-name option-data;
**
**   This  identifies a DHCPv6 client in a host statement.  option-name is
**   any option, and option-data is the value  for  the  option  that the
**   client will send. The option-data must be a constant value.

There's also no mention of host-identifier working for IPv4 addresses
in the RELNOTES file in the 4.2.3 tarball.

> As an example for the archives you can do things like this since isc
> dhcp version 4 something:
> 
> 	host foo {
> 	    host-identifier option agent.circuit-id "foo";
> 	    fixed-address 192.0.2.17;
> 	}
> 
> This will work fine whatever the client mac is and even if it changes as
> it uses host-identifier and not mac as identity.

Can you set the host identifier to be the combination of the agent.ciruit-id
and the agent.remote-id?  Or do you have to specify a separate class/pool
for each switch?

	-- Ed