Cisco VOIP Mitigation
by danlor on Dec.14, 2004, under Technology
I’ve been working with HP trying to figure out what we can do here about these phones. It is not a simple problem. Most hardware can deal with multi-link loopback conditions using technology like spanning tree, but how the hell do you handle a loopback on the same link? It is technically impossible to do unless you actually go ahead and create a cable with shorted out pins, or litterally looped the wires back into the connector. It is not condition you would normally ever see by accident.
So far I have had limited success. Spanning tree has been usefull in limiting how many loopbacks I get on the switch. It will shut down all loopbacked ports except one. The second step was to turn on flood control (throttling). This keeps the ports from shutting down the entire switch with broadcast storms.
The final solution is to get HP to patch the switch to sense this insane condition and shut down the port. I have no idea when I will get that.
