Nas-Ip-Address attribute and source IP address of UDP datagram.

Alan DeKok aland at
Thu Jan 22 16:39:28 CET 2009

Dmitry V. Krivenok wrote:
> I deal with bad "hand-made" NAS, which doesn't include "Nas-Ip-Address"
> attribute into the packet.
> So I can't distinguish packets from different NAS'es.

  Look at Packet-Src-IP-Address.  It is a "virtual" attribute that you
can use in dynamic expansions.

> Is there a way to add this attribute (with value of source address of
> UDP datagram) using standard FreeRadius facilities?
> We don't use proxies, so this solution seems to be correct.

	if (!NAS-IP-Address) {
		update request {
			NAS-IP-Address = "%{Packet-Src-IP-Address}"

> I'm writing my own rlm and I can implement desired functionality if
> there is no one in FreeRadius.
> The problem lies in that I can't find the address of client in REQUEST
> (i.e.  auth_req) structure.


  Alan Dekok.

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