Concurrent DHCP Servers and IP Conflicts

[gaby]

Is it possible to have multiple concurrent coredhcpservers using the same file_leases.txt file, or would I need multiple coredhcp service different ranges for this to work?

I'm wondering how to integrate this with dhcplb

[Natolumin]

This really depends on the plugin you end up using. Ideally the concurrency considerations would be something that's documented per each plugin, but we don't really have that today yet

Using the file plugin, which doesn't keep internal state per lease, you can have multiple servers on the network sourcing from the same mac -> ip mapping, and either an lb or the serverid plugin will ensure only one server answers it at any time

If using something like the range plugin, that holds some lease association for clients in its internal state. If multiple servers own the same range they can disagree on which clients holds leases for each address so you definitely want disjoint address spaces there, and ideally if you use a loadbalancer, a deterministic client -> backend mapping

Other plugins may use a shared database to resolve conflicts (I think the redis one does that) in which case you can again have multiple servers serving the same range