Tool for DHCP pool statistics/monitoring

Leif Arne Neset leifa at
Tue Apr 15 07:58:07 UTC 2008

Trond Hasle Amundsen skrev:
> Hi,
> This is an announcement of sorts.
> I've searched and looked for a tool that lets me monitor DHCP pools,
> and possibly get a notification before the pool is full and users
> start complaining. But without luck, so I decided to make my own. I'm
> making the script publicly available, in case someone else is
> interested:
> The script (written in perl) reads dhcpd.conf and dhcpd.leases, and
> will output statistics for each subnet and pool. It can also function
> as a Nagios service and Munin plugin. Details on the web page above.
> It can possibly be extended to do more.
> The script is completely safe and doesn't try to do nasty stuff. Let
> me know if you like it and/or have feature requests, patches etc.
> Cheers,

Nice tool, but I have a small comment.

If you have a lot of pools or a large leasefile, this can generate huge 
load on the server. We did something like you do but, switched to a 
system where we generate a table of of all the pools with usage (active 
leases and pool size) and  store it in a cache file. When MRTG asks for 
the numbers for a pool, the server only checks this file unless the file 
is more than 5 minutes old. If the cache file is more than 5 minutes old 
a new file is beeing generated. This scales much better. Currently we 
run this application on a system with more than 100.000 leases, 550 
pools and about 70 groups of pools beeing checked by MRTG every 15 min.

Leif Arne Neset
leifa at

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