Watching performance on a DHCP Server

Olaf van der Spek olafvdspek at
Mon Feb 11 21:55:24 UTC 2008

On Feb 11, 2008 7:49 PM, Blake Hudson <blake at> wrote:
> You may want to review the thread from the beginning. My network currently
> has 10,000+ DHCP clients (and I plan on accommodating double that within the
> lifetime of this server). I have a beefy server (4x 3.0GHz Xeon, 2x 15k
> RAID1) and it was only able to reliably handle 10 to 20 4-way discover

Isn't that too much CPU power, too little HDD power for this job?

> handshakes a second, 2-way handshakes were maybe double or triple those
> numbers. When pounded by DHCP requests, it's possible that even less are
> processed in a timely manner due to collisions, timeouts, etc.
>  The potential convergence time concerns me if there were an enterprise wide
> prolonged outage. Increasing the lease time means less leases processed on a
> regular basis (not as much of a concern) as well as reducing the need for a
> 4 way handshake and being able to use a 2 way handshake if a prolonged
> outage occurs (my main concern I'd like to accommodate).

I just read the thread and the disk IO indeed changes the game. ;)
Still, the gap between theoretical top performance and actual
performance seems extreme.
Even if you have the requirement that leases have to be committed to
disk before you respond to the client.

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