[Dnsmasq-discuss] Does Dnsmasq support Option 82?

Simon Kelley simon at thekelleys.org.uk
Thu Mar 1 16:22:16 GMT 2007


scoob8000 wrote:
> Simple question.   Does Dnsmasq support option 82?
> 
> Option 82 lets you make a reservation for a specific port on an ethernet
> device.   So regardless of the MAC of the device you connect, it always
> gets
> the same IP as long as it's in that port.
> 
> Even better, if it does and anyone knows what I'm talking about, could you
> share your config file?  :)
> 
> Thanks
> Mike

This is the stuff specified by RFC 3046, right? The very basic server
functionality is supported, quote:

   DHCP servers claiming to support the Relay Agent Information option
   SHALL echo the entire contents of the Relay Agent Information option
   in all replies.  Servers SHOULD copy the Relay Agent Information
   option as the last DHCP option in the response.  Servers SHALL NOT
   place the echoed Relay Agent Information option in the overloaded
   sname or file fields.  If a server is unable to copy a full Relay
   Agent Information field into a response, it SHALL send the response
   without the Relay Information Field, and SHOULD increment an error
   counter for the situation.

That behaviour is implemented with the exception of the error counter stuff.


This function, quote:

   Servers MAY use the Circuit ID for IP and other parameter assignment
   policies.  The Circuit ID SHOULD be considered an opaque value, with
   policies based on exact string match only; that is, the Circuit ID
   SHOULD NOT be internally parsed by the server.

   The DHCP server SHOULD report the Agent Circuit ID value of current
   leases in statistical reports (including its MIB) and in logs.  Since
   the Circuit ID is local only to a particular relay agent, a circuit
   ID should be qualified with the giaddr value that identifies the
   relay agent.

is NOT implemented, and may be what you need. Given that the framework
is there, doing it shouldn't be difficult.


Does that make sense?


Cheers,

Simon.





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