5406zl freezes with all lights on

[Kevin D'Arbela]

We have had a few instances recently, where our fairly new 5406zl switch hangs/freezes (it cannot respond to pings, etc). All the lights on the connected ports are stuck on. The only way round it is to power it off and back on. The PCM identifies Major severity "High collision or drop rate (formerly overbandwidth)" events just before the outage.

We managed to narrow down the port that this error was being generated on, being a CCTV DVR. Once it was disconnected from the switch, there were no further instances.

Is there any way of preventing this hanging, and perhaps isolating the misbehaving device without affecting the whole network?

Thanks in advance.

Kevin

[Drew Redman · Accepted solution]

What version of firmware is the 5400 running?

It sounds like the DVR may be generating a broadcast storm. You will generally see 'High Collision or Drop Rate' and 'Excessive Broadcast' FFI's when this happens. In this case, isolating the device on its own vlan would stop it from taking down the rest of your network.

You might also want to investigate whether the DVR device is multicasting, in which case enabling IGMP can be helpful. Without IGMP enabled, the switch treats multicast traffic as broadcasts.

In any case, the DVR probably shouldn't be doing what its doing so I'd recommend looking into that as well.

[Kevin D'Arbela]

Hi,

The 5400 is running as follows:

ROM: K.12.12
SW Version: K.13.63

Having the DVR looked into by the manufacturers, and the VLAN suggestion sounds like a good one.

Thanks, Drew.

[Drew Redman]

No problem. You're on the newest code.. I haven't heard anything (or seen anything in release notes) about the switch freezing related to high droprate, so my bet would be that it's just a broadcast storm taking down the subnet.

[Kevin D'Arbela]

Thanks, again.