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-------- Original Message --------<br>
Subject: Re: Watching performance on a DHCP Server<br>
From: Olaf van der Spek <a class="moz-txt-link-rfc2396E" href="mailto:olafvdspek@gmail.com"><olafvdspek@gmail.com></a><br>
To: <a class="moz-txt-link-abbreviated" href="mailto:dhcp-users@isc.org">dhcp-users@isc.org</a><br>
Date: Monday, February 11, 2008 11:21:01 AM<br>
<blockquote
cite="mid:b2cc26e40802110921p7181cce8m788b50fbeee11bcd@mail.gmail.com"
type="cite">
<pre wrap="">Blake Hudson wrote:
</pre>
<blockquote type="cite">
<pre wrap="">rapidly (keeping IP pool usage as low as possible). The main
advantage to longer lease times being load on the DHCP server. If I
</pre>
</blockquote>
<pre wrap=""><!---->
Load?
Isn't that only really an issue when you have a lot of clients (1000+
or 10000+)?
Olaf
</pre>
</blockquote>
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 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. <br>
<br>
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).<br>
<br>
-Blake<br>
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