DHCP relay - process replies (DHCP-Offer, DHCP-Ack...)

Chaigneau, Nicolas nicolas.chaigneau at capgemini.com
Thu Oct 12 14:44:20 CEST 2017

> > 
> > Actually this seems to be another issue.
> > The DHCP Server is not responding to my FreeRADIUS DHCP relay, but to the previous relay.
>   That's how DHCP works.  It's horrible.
>   The DHCP servers respond to the giaddr, not to the source IP of the packet.


But in the virtual server configuration, the giaddr is supposed to be changed:

		update request {
			# IP Address of the DHCP relay (ourselves)
			&DHCP-Gateway-IP-Address :=

This doesn't work, however. The network capture shows that giaddr was not changed in the relayed packet.
I thought maybe it's because "request" is the initial packet received, so I need to update the "proxy request".
So I tried:

		update proxy-request {
			# IP Address of the DHCP relay (ourselves)
			&DHCP-Gateway-IP-Address :=

But it doesn't work either, in this case I get the following errors:

Thu Oct 12 11:54:25 2017 : WARNING: (0)       List "proxy-request" is not available
Thu Oct 12 11:54:25 2017 : ERROR: (0)       Mapping "" -> "&DHCP-Gateway-IP-Address" invalid in this context

What is the correct way to have FreeRADIUS behave as a DHCP relay ?
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