option 82 feature of DHCP

[Glenn Satchell]

Following the google suggestion, the first hit gives this snippet which
looks like exactly what you want. I think the man pages are a behind the
times as they don't mention this. If your circuit-id is binary then you
can use a sequence of colon separated hex digit pairs to represent it.

"Starting from ISC DHCPD version 4.2, you can match on agent.circuit-id as
well, by using this syntax:

	host client-name-1 {
		host-identifier option agent.circuit-id "dslam42.port22";
		fixed-address 192.168.0.6;
	}
Unfortunately, at this time, the "host-identifier option ..." statement
only works with agent.circuit-id."

regards,
-glenn
On Fri, July 4, 2014 12:47 am, Han Koster wrote:
> Hi,
>
> I am confused, on both the question and the answer.
> The confusion is about the used terms, server switch etc. I think the
> following is meant:
>
> 1. The dhcp client send the discover and request
> 2. The access switch adds a portid/circuitid or whatever in option 82
> 3. The requester wants the dhcp server to use this id to assign an ip (and
> not use mac)
>
> It would be nice when this could be configured in the dhcp server. But
> afaik that is not possible with the current/latest version, so you have to
> modify the code yourself.
> Be aware that you must be sure that only one client is possible on the
> port of the access switch.
> Or the switch must combine portid and mac address in the option 82 id to
> create something unique.
>
> Regards,
>
> Han Koster
>
> ________________________________________
> From: dhcp-users-bounces at lists.isc.org [dhcp-users-bounces at lists.isc.org]
> on behalf of Peter Rathlev [peter at rathlev.dk]
> Sent: 03 July 2014 07:48
> To: Users of ISC DHCP
> Subject: Re: option 82 feature of DHCP
>
> On Thu, 2014-07-03 at 04:50 +0000, Hardik.V.Shah at ril.com wrote:
>> I am configuring DHCP server with enabling option 82 features on
>> network switches. My goal is to assign an IP to the server based on
>> server’s serial number which I can get it through option 82.
>>
>> Can someone advise if it is possible and how?
>
> Option 82 is typically something that the first switch injects into the
> DHCP discover/request that the server sends out. The injection happens
> in the switch so it can contain information that the server couldn't
> know itself.
>
> The serial number of the server sounds like something the server would
> know and the switch would not know.
>
> If the switch can really see the serial number then yes, it is possible.
> The Internet is filled with examples of how to do it. Just search for
> "isc dhcp option 82" in your favourite search engine.
>
> Are asking because "host" statements cannot select on a random option?
>
> --
> Peter
>