How to sync a Linux secondary DHCP server?

Sandra Schlichting littlesandra88 at
Wed Aug 1 14:33:47 UTC 2018

> > So if I made sure that each dhcp server served dynamic leases in
> > different ranges, so no overlap, would it then be a good setup?
> Yes you could do that. But I can think of a few problems:
> If one server was faster it could have more of the clients getting
> addresses from it and fewer from the second server. There is no load
> balancing or sharing.

That would be acceptable in my setup.

> If one server is shutdown or fails, then the clients would eventually
> expire their leases, and would get a different address frm the other
> server. So persistent connections, such as ssh, web page logns, etc, would
> disconenct or need to re-authenticate.

Hmm. Ok, that is not optimal.

> While failover might look difficult, it is actually quite simple to set up
> and works very reliably. The failover code has been around for a really
> long time, early 2000s, so all the kinks have been well and truly worked
> out.

Based on Paul's reply, I got the impression that the failover were
risky, when he wrote:

DHCP failover is a very fragile protocol under failure. It works
amazingly well under normal circumstances but if you ever get to the
point where you're thinking about doing partner-down, be prepared to
have resync take hours or lose leases.

But that is not your experience, I can guess?

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