[Kea-users] Configuring kea for relayed subnets *not* on its own interface's address

[Francis Dupont]

> In the older dhcpd server, this is an unfortunate result of the assumption
> that the DHCP is serving DHCP on the subnet it is connected to.  I would
> have hoped that kea would have fixed that.  (Or can someone explain why it
> is needed?)

=> it is a bit worse: ISC DHCP has a loose notion of servicing interfaces
when Kea has a strong one. There is another difference about interfaces
than the one you described: in ISC DHCP the list of interfaces to
serve is in command line arguments, in Kea it is in the config file.
As a result when you translate ISC DHCP configs using the tool in
general you get this warning at the top of the generated kea config file:
  /// This configuration declares some subnets but has no interfaces-config
  /// Reference Kea #5256
Even it is legal to have no interfaces-config clause in Kea it won't work
and without any interface in ISC DHCP config the tool can't infer the
interface list...

Regards

Francis Dupont <fdupont at isc.org>

PS: in Jeff's case it is better to select subnets using relay addresses
than using the receiving interface because a priori relays serve
different physical subnets so should not share the same pool.