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.
> 


Yes.

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 := 10.11.19.12
		}

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 := 10.11.19.12
		}

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 "10.11.19.12" -> "&DHCP-Gateway-IP-Address" invalid in this context



What is the correct way to have FreeRADIUS behave as a DHCP relay ?
This message contains information that may be privileged or confidential and is the property of the Capgemini Group. It is intended only for the person to whom it is addressed. If you are not the intended recipient, you are not authorized to read, print, retain, copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message.



More information about the Freeradius-Users mailing list