atom feed35 messages in org.isc.lists.dhcp-usersRe: host-identifier and option 82
FromSent OnAttachments
Michal VančoJan 26, 2012 3:10 pm 
Glenn SatchellJan 26, 2012 6:53 pm 
Michal VančoJan 26, 2012 11:33 pm 
Michal VančoJan 27, 2012 1:20 am 
David ForrestJan 27, 2012 3:06 am 
Michal VančoJan 27, 2012 3:34 am 
Glenn SatchellJan 27, 2012 3:42 am 
Michal VančoJan 27, 2012 3:56 am 
Simon HobsonJan 27, 2012 4:30 am 
Michal VančoJan 27, 2012 5:03 am 
Simon HobsonJan 27, 2012 6:15 am 
Michal VančoJan 27, 2012 10:14 am 
Simon HobsonJan 27, 2012 10:40 am 
Michal VančoJan 27, 2012 10:51 am 
Ed RavinJan 27, 2012 11:31 am 
Christian KratzerJan 28, 2012 4:19 am 
Ed RavinJan 28, 2012 10:58 am 
Frank BulkJan 28, 2012 11:04 am 
Michal VančoJan 28, 2012 11:26 am 
Simon HobsonJan 28, 2012 11:43 am 
Michal VančoJan 28, 2012 11:53 am 
Michal VančoJan 28, 2012 12:00 pm 
Matej MailingJan 28, 2012 2:10 pm 
Michal VančoJan 28, 2012 2:27 pm 
Christian KratzerJan 28, 2012 2:35 pm 
Matej MailingJan 28, 2012 2:35 pm 
Christian KratzerJan 28, 2012 2:50 pm 
Alex MoenJan 28, 2012 3:14 pm 
Christian KratzerJan 29, 2012 12:26 am 
Marc PereaJan 30, 2012 11:28 am 
Christian KratzerJan 30, 2012 12:10 pm 
Alex MoenJan 30, 2012 12:33 pm 
Christian KratzerJan 30, 2012 1:08 pm 
Michal VančoFeb 2, 2012 11:42 am 
David GanorFeb 5, 2012 1:07 am 
Subject:Re: host-identifier and option 82
From:Michal Vančo (mva@di-vision.sk)
Date:Jan 27, 2012 1:20:53 am
List:org.isc.lists.dhcp-users

Replying to myself …

wouldn't help here to use infinite lease times to prevent client doing renewal?
what happens in case client changes MAC (dualboot, different PC, different
router, whatever)? will this work?

michal

Hi Glen,

yes I know about stash-agent-options flag. And I also know what its purpose is. Despite this fact, what happens when you restart DHCP server? What I know is,
that no information about static leases (static host entries) is written into lease file. Hence server
will forget all stashed agent options and the client will not be able to renew its address. This is what I probably
see when my logfile starts to fill with "unknown lease" messages after I restart server.

regards -michal

On 27.1.2012, at 3:53, Glenn Satchell wrote:

Hi Michal

There is a dhcp server configuration option to cover this very case, from the dhcpd.conf man page:

stash-agent-options flag;

If the stash-agent-options parameter is true for a given client, the server will record the relay agent information options sent during the client's initial DHCPREQUEST message when the client was in the SELECT- ING state and behave as if those options are included in all subsequent DHCPREQUEST messages sent in the RENEWING state. This works around a problem with relay agent information options, which is that they usually not appear in DHCPREQUEST messages sent by the client in the RENEWING state, because such messages are unicast directly to the server and not sent through a relay agent.

regards, -glenn

Hi,

I've just tried to use host-identifier to assign static IPv4 address based on option 82 agent.remote-id like this:

host hostname { host-identifier option agent.remote-id XX:XX:XX:XX:XX:XX; fixed-address aaa.aaa.aaa.aaa; }

this apparently works until client renews its IP address. DHCPREQUEST is going directly from client to server bypassing relay agent which means that there is no option 82 inserted when client is trying to renew address. So server is unable to match DHCPREQUEST against host declaration. Am I right in this? Is there any workaround? Any clue?

thanks michal