Example config with option 82, bogus relays

[Glenn Satchell]

>Date: Tue, 17 Jun 2008 09:18:27 -0400
>Subject: Re: Example config with option 82, bogus relays
>From: Joe Polcari <jpolcari at bluesocket.com>
>To: <dhcp-users at isc.org>
>
>As a side note - I just want to understand what is being discussed.
>What is circuit-id?
>

Hi Joe

These are extra values that a relay agent, eg router, some switches, or
computer running dhcrelay can add to a dhcp packet when it forwards it
to the dhcp server. They get stored in dhcp option 82, hence the reason
they are sometime called option 82.

The circuit-id usually is some representation of the port the request
came in on, while the remote-id is a descriptor for the remote host.

Some sites use this information to assign given IP addresses to
particular ports on a switch, or for an ISP to their DSL customers.

For more detains have a look at the dhcp-options man page, and scroll
down to the section titled "RELAY AGENT INFORMATION OPTION" where it
explains all the technical details.

regards,
-glenn