DHCP Performance

[sthaug at nethelp.no]

From: Jason Antman <jantman at oit.rutgers.edu>
> We're starting to get into some more depth troubleshooting DHCP
> performance issues - not just startup, but running as well. Our DHCP
> server (yes, singular) supports a network with approx. 15,000 users, all
> DHCP'ed. During peak times (usually once or twice a day), we see upwards
> of 2-3k requests in a 15-30 minute interval.

Typically 10 - 25 DISCOVERs and 4 - 10 REQUESTs per second here. Peak
load (typically when some client goes bananas) can be much higher
(e.g. today for 2-3 minutes we had a burst of arund 100 REQUEST/ACKs
per second).

> Does anyone else out there have an idea of the load that their dhcpd
> instance is handling? Has anyone else with sustained loads around 1-3
> RPS had issues? Is anyone else running something on the order of 400+
> subnets and 10000+ clients?

300+ subnets and 130K leases here, running 4.1.1 on a failover pair
with Dell hardware, RAID disks. No problems at all here. As others have
pointed out your disk I/O performance is important.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no