Garbage collection?

Peter Laws plaws at
Wed Sep 9 14:24:58 UTC 2009

Glenn Satchell wrote:

> Every hour or so dhcpd re-writes the leases file with only the last
> record for each lease. This helps keep the file from growing too big.

OK.  Knew about how the leases file was structured but didn't realize that 
the file was just, essentially, a "hints" file for when the daemon 
restarted since it's really all in memory.

This is clearly why all the scripts out there caution you about their 
"outstanding leases" count not always being accurate.

> By the way dhcpd-3.0.1 is very old, released in July 2004, so you
> should think about an upgrade. But then I see you are running RedHat 3,
> so perhaps there is more than a dhcpd upgrade required? :)

Don't get me started ... :-)  Yes, we know.

Lease time was 3600 and has been cut in half now.  Since that pool is all 
WiFi, no one will likely notice ... except that we won't come as close to 
running out.  Hopefully.


Peter Laws / N5UWY
National Weather Center / Network Operations Center
University of Oklahoma Information Technology
plaws at
Feedback? Contact my director, Craig Cochell, craigc at Thank you!

More information about the dhcp-users mailing list