I'm not sure if this is the right forum, and strictly speaking it's not Linux related, but here goes....

Does anyone know what would make a Windows client machine issue a DHCPREQUEST to renew its lease every 15 minutes? I'm not 100% sure that I'm dealing with a Windows client, but I'm at least 95% sure.

We're using ISC dhcpd on Slackware with a default lease time of 48 hours, maximum of 48 hours, and minimum of 5 minutes. The config is pretty standard, with one load-balanced peer.

The clients are students in dorms, so I have no access to the machines to see what's up, but in the past week I've noticed a couple of machines making requests every 15 minutes.

The reason I'm curious is that there are some other odd behaviors related to caching that these clients seem to be exhibiting and I'm starting to see a pattern.

Googling hasn't helped, so if anyone has seen this I'd be appreciative for any insight you could provide.

I know this doesn't really help, but why exactly does this seem like a bad thing? A few dozen packets per hour... ?

--- rod.

rod,

It's not a big deal as far as the load is concerned. The load on the servers is low, as is the traffic.

What's odd is that while every other client on our network was unaffected by shutting down one of the redundant DHCP servers (see RFC 2131), only the clients exhibitng this behavior had problems getting an address from the secondary server.

We're wondering what is causing this behavior. Some things we consider candidates are P2P apps, games, or possibly "security suites" (bloatware).

Any guesses anyone?

Thanks in advance.

Could be IRC clients...or IRC botservers. Also Bit torrent clients could be constantly checking the DHCP lease for connectivity.

I am curious to see if the activity will stop once the students go home for the summer.

Try to log the mac addresses of these clients and see if they show up in a different lan segment in the fall.