Comments on: Storm Control http://aconaway.com/2008/05/15/storm-control/ Not something you want to hear Thu, 21 Aug 2008 22:30:37 +0000 http://wordpress.org/?v=2.2.1 By: Aaron Conaway http://aconaway.com/2008/05/15/storm-control/#comment-1846 Aaron Conaway Sat, 31 May 2008 02:41:02 +0000 http://aconaway.com/2008/05/15/storm-control/#comment-1846 No doubt. When this happened, I turned off spanning tree on a 2950, plugged a crossover cable from f0/1 to f0/2, and plugged in my Windows laptop to f0/3. I started to ping the IP of the switch, but, before five packets came back, the switch completely stopped responding. When I unplugged my laptop, it came back. It was pretty cool, actually. :) No doubt. When this happened, I turned off spanning tree on a 2950, plugged a crossover cable from f0/1 to f0/2, and plugged in my Windows laptop to f0/3. I started to ping the IP of the switch, but, before five packets came back, the switch completely stopped responding. When I unplugged my laptop, it came back. It was pretty cool, actually. :)

]]> By: Bubba-Jay http://aconaway.com/2008/05/15/storm-control/#comment-1845 Bubba-Jay Sat, 31 May 2008 02:35:24 +0000 http://aconaway.com/2008/05/15/storm-control/#comment-1845 I guess it doesn't take much broadcast traffic in order for a lethal storm to get started. Taking down several newer switches like that is no joke! I guess it doesn’t take much broadcast traffic in order for a lethal storm to get started. Taking down several newer switches like that is no joke!

]]> By: Aaron Conaway http://aconaway.com/2008/05/15/storm-control/#comment-1347 Aaron Conaway Fri, 23 May 2008 11:49:12 +0000 http://aconaway.com/2008/05/15/storm-control/#comment-1347 Bubba-jay: Right-o -- hubs are alright as long as you don't get any loops. BTW, I edited the article for a little more clarity. Bubba-jay: Right-o — hubs are alright as long as you don’t get any loops. BTW, I edited the article for a little more clarity.

]]> By: bubba-jay http://aconaway.com/2008/05/15/storm-control/#comment-1323 bubba-jay Fri, 23 May 2008 00:29:02 +0000 http://aconaway.com/2008/05/15/storm-control/#comment-1323 I wasn't exactly clear on how the hub got connected twice to your switch fabric, but I guess somehow it was and that's what caused the switching loops you're talking about. Absent that second uplink to your switches, you'd probably be OK with that hub connected. I wasn’t exactly clear on how the hub got connected twice to your switch fabric, but I guess somehow it was and that’s what caused the switching loops you’re talking about. Absent that second uplink to your switches, you’d probably be OK with that hub connected.

]]> By: Aaron Conaway http://aconaway.com/2008/05/15/storm-control/#comment-1104 Aaron Conaway Thu, 15 May 2008 17:20:13 +0000 http://aconaway.com/2008/05/15/storm-control/#comment-1104 Absolutely right, Sebastian. That would fix the problem of hooking up random switches and ill-fated hubs to the network. Absolutely right, Sebastian. That would fix the problem of hooking up random switches and ill-fated hubs to the network.

]]> By: Sebastian Graf http://aconaway.com/2008/05/15/storm-control/#comment-1103 Sebastian Graf Thu, 15 May 2008 17:02:27 +0000 http://aconaway.com/2008/05/15/storm-control/#comment-1103 Hi Aaron, in this specific situation you would get the same benefit with Spanning Tree BPDU Guard, assuming the ports attached to the hub were configured with portfast. This way you do not need to worry about the correct levels of broadcasts/unicasts/multicasts. The port will just be disabled if it recieves a BPDU, which would obviously happen in the situation you described above. Hi Aaron,

in this specific situation you would get the same benefit with Spanning Tree BPDU Guard, assuming the ports attached to the hub were configured with portfast.

This way you do not need to worry about the correct levels of broadcasts/unicasts/multicasts. The port will just be disabled if it recieves a BPDU, which would obviously happen in the situation you described above.

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