[Kea-users] Bind service to loopback address

[Tomek Mrugalski]

W dniu 19.04.2017 o 16:35, Jason Guy pisze:
> I would like to leverage my routing on the host setup, and bind the kea
> service to the loopback address I have configured. This would ultimately
> allow me to deploy multiple kea servers with an "anycast" reachability.
> 
> ip addr show lo
> ...
>     inet 10.50.5.11/32 <http://10.50.5.11/32> brd 10.50.5.11 scope
> global lo:1
> ...
> 
> Kea.conf:
> ...
>         "interfaces-config": {
>             "interfaces": [
>                 "lo/10.50.5.11 <http://10.50.5.11>",
>                 "eth0",
>                 "eth1"
>             ]
>         },
> ....
> 
> I have tried specifying this in a few ways, and the DHCP relay packets
> reach the server, but Kea does not appear to process them. I thought
> about putting the loopback on the ethernet interfaces as secondary
> addresses, but wanted to understand why I can see the relay packets
> arrive but not picked up by Kea.
Kea uses raw sockets by default to receive DHCPv4 traffic. Raw sockets
receive raw packets, i.e. everything that comes over wire (ethernet
header, ip, udp and everything that follows). This is different on
loopback as there's no notion of ethernet headers there. Kea has some
support for loopback traffic handling, but it's not used extensively, so
did not receive much testing.

Have you tried setting dhcp-socket-type to udp? If that doesn't help at
all, can you open a ticket for this?

Tomek