We recently endured a series of broadcast storms that caused our ISP to shut us down for brief periods of time. After going through a multitude of tests, we determined that the issue was related to Intel NIC drivers on some new HP desktop computers we'd recently purchased.
The broadcast storm would occur if the desktop PC went into sleep mode for an extended period of time. We had one PC push out several gigs of network traffic in a matter of seconds. Strangely, we had eight new PC's all on a configuration bench and all were in sleep mode but only three of them were causing the storm. The randomness of the problem made it that much more difficult to diagnose.
This problem first popped up around a year ago with the Intel i217-LM NIC drivers. Some users on a Cisco message board
were suggesting that the solution was to disable IPv6, but this did not work. In fact, we disabled IPv6 across our whole network thinking this would stop the broadcast storms but we got another one the very next day. What's so odd about all this is that you have the leading manufacturer of PC's (HP) using a motherboard with one of the leading manufacturers of NIC drivers (Intel) and all running the world's most popular desktop PC OS (Windows) and the problem stil persists.
Upgrading the NIC drivers is the only solution here. However, you can't count on Windows Update to give it to you. This means you nead to visit Intel's site
and manually download the drivers, then uninstall your current ones and reinstall the newly downloaded drivers. PC manufacturers like HP need to be more proactive in loading the most current NIC drivers before they ship in order to save their customers from this kind of headache.