Eval statement by relay

Claus Holm Christensen iscdhcp at claushc.dk
Tue May 27 21:48:22 UTC 2008

Blake Hudson skrev:
> Can relay agent IP address (giaddr) be used to match against in an 
> evaluation statement? I've reviewed man dhcp-eval, but I don't see any 
> mention of giaddr, but it seems logical it could be extracted somehow.

I tried to use it in a match statement with 3.0.5 or .6, to no avail, 
but 3.0.7 has this promising little comment in the release notes:

> A bug was fixed where the 'giaddr' may be used to find the client's subnet rather than its own 'ciaddr'.

I haven't checked it yet, but it would be a really nice feature.

You will have to use something like packet(20,4) to find the giaddr 
(look up the correct offset in the specs), and then it might be a good 
idea to do some binary-to-ascii() on it to make it readable. I think it 
returned all-ones or all-zeroes in previous versions.

Claus Holm Christensen

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