[Kea-users] Running Kea with unreliable interfaces?

[Francis Dupont]

Shane Kerr writes:
> I had a problem with Kea on a server that has 2 interfaces. One of the
> interfaces did not survive a reboot (due to a bogus USB cable, but it
> could be any reason). 
> 
> Kea did not start because the interface was missing:
> 
> 2016-02-15 15:03:24.366 ERROR [kea-dhcp4.dhcp4/510] DHCP4_INIT_FAIL failed to
>  initialize Kea server: configuration error using file '/opt/kea-git/etc/kea/
> kea.conf': Failed to select interface: interface 'wlan-awus036ac' doesn't exi
> st in the system (/opt/kea-git/etc/kea/kea.conf:14:20) (/opt/kea-git/etc/kea/
> kea.conf:14:20)

=> I am afraid this is axactly what you should have expected...

> This meant that the other network was also missing a DHCP server.
> (Luckily this is just my home network, and all other users were at work
> or school.)
> 
> What's the best way to deal with this potential problem? Should I run
> two separate instances of Kea, using different configuration files, one
> per interface? Or...?

=> if the unreliability is only between reboots IMHO the simplest is
to check if the interface is available in a script. If it can happen
at any time you need two independent instances (2 processes, 2 config
files, 2 lease files, 2 log files, etc, and bind the service socket
to the served interface (i.e., SO_BINDTODEVICE & co are your friends).

Regards

Francis Dupont <fdupont at isc.org>