[Kea-users] Why aren't remote-id, circuit-id, and interface-id treated the same for v4 and v6?

Francis Dupont fdupont at isc.org
Tue Jan 9 10:04:26 UTC 2018


According to RFC 3315 (I didn't check if its update was already published)
the interface ID (DHCPv6 option 18) identifies a link, not a client on
a link:

22.18. Interface-Id Option

   The relay agent MAY send the Interface-id option to identify the
   interface on which the client message was received.  If a relay agent
   receives a Relay-reply message with an Interface-id option, the relay
   agent relays the message to the client through the interface
   identified by the option.
	       
so it is used in Kea to select a subnet.

Now if you want to use it as an identifier for host reservation the
obvious solution is the flex-id hook library...

Note the standard way to identify a dual-stack client is to use client ID
options. For old DHCPv4 clients which don't know it you still have the
hardware address: the problem is on the DHCPv6 side but there are a lot
of ways to get the client hardware address including Cisco proprietary
relay option...

Regards

Francis Dupont <fdupont at isc.org>



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