[Kea-users] DHCP redundancy

[John Ratliff]

I'm seeking best practice advice on how to setup DHCP server redundancy 
with kea.

With ISC DHCP, I used VRRP with two servers and configured it to send 
the dhcp-server-identifier option as the VRRP IP. Then I would run a 
script that sync'd the lease database automatically via cron.

This process is messy and error prone, so I would like to use kea instead.

The subnets I am allocating via DHCP is not the same subnet that the 
server is in, so we use ip-helper statements to forward DHCP requests to 
the server.

I have kea using mySQL as a lease backend. The mySQL server is not on 
the same machine as kea.

My first thought was to use VRRP and supply the dhcp-server-identifier 
option again. I ran into a problem though that if kea started before 
VRRP, it wouldn't listen on the VRRP IP. There is probably a solution to 
that, but I don't have one yet.

So then I changed the router configuration to use two ip-helper 
statements, sending the request to both primary and secondary kea 
servers; I also removed the dhcp-server-identifier option. This seems to 
work.

Is this a reasonable setup for DHCP redundancy with kea? Is there a 
better option I might want to consider? Are there any concerns I should 
be aware of with both servers being active?

Thanks.