DHCP-Relay-Agent-Information in reply

[Alexandr Sviridov]

Hello

I'm playing with freeradius dhcp support, and get the following problem.

Freeradius 2.1.7, option 82, for dhcp snooping to work I have not only get 
DHCP-Relay-Agent-Information (option 82) in request but send it back to dhcp 
relay.
Just test examle (radiusd in debug mode):
DHCP-Discover:
         DHCP-Opcode = Client-Message
         DHCP-Hardware-Type = Ethernet
 	...skip...
         DHCP-Parameter-Request-List = DHCP-Domain-Name-Server
         DHCP-Relay-Agent-Information = 0x010600040001000202080006001e589e836f
DHCP-Offer:
Sending DHCP-Offer of id 69dd544f from 1.1.1.1:67 to 1.1.1.2:67
         DHCP-Opcode = Server-Message
         DHCP-Hardware-Type = Ethernet
 	...skip...
         DHCP-IP-Address-Lease-Time = 3600
         DHCP-Relay-Agent-Information = 0x010600040001000202080006001e589e836f

So far, so good, but tcpdump shows me:
DHCP-Discover:
            Agent-Information Option 82, length 18:
               Circuit-ID SubOption 1, length 6: \000\004\000\001\000\002
               Unknown SubOption 2, length 8:
                 0x0000:  0006 001e 589e 836f
DHCP-Offer:
             Agent-Information Option 82, length 20:
               Unknown SubOption 0, length 18:

So as I can see option 82 length is 20 instead of 18. Why?



-- 
Alexandr Sviridov