Comments on: Storm Control http://aconaway.com/2008/05/15/storm-control/ It's possible that someone somewhere needs to see this. Fri, 10 Feb 2012 13:52:17 -0700 hourly 1 http://wordpress.org/?v=3.1.4 By: Tushar http://aconaway.com/2008/05/15/storm-control/comment-page-1/#comment-32354 Tushar Sun, 26 Sep 2010 10:42:52 +0000 http://aconaway.com/2008/05/15/storm-control/#comment-32354 Hey guys, We have similar issue in our network. We are using Dell power connect switches & Avaya Phones in our network.  Sometimes users connect both ports of Avaya phone to a 8 port switch, which makes loop in network & whole site goes down. We already have STP running but it doesn't work as Avaya phone works like a hub. Is there any solution for this issue.   Hey guys,
We have similar issue in our network.
We are using Dell power connect switches & Avaya Phones in our network.
 Sometimes users connect both ports of Avaya phone to a 8 port switch, which makes loop in network & whole site goes down. We already have STP running but it doesn't work as Avaya phone works like a hub. Is there any solution for this issue.  

]]> By: Roger http://aconaway.com/2008/05/15/storm-control/comment-page-1/#comment-23387 Roger Tue, 08 Jun 2010 11:00:51 +0000 http://aconaway.com/2008/05/15/storm-control/#comment-23387 Just reading a bit here. A really nasty issue is when a single miniswitch or hub is looped on the hub itself and has only a single link to your switched fabric. BPDU Guard does not readily work here but a storm control of 20 will. We have also found a unicast level (like in the description above) set to about 30 will suffice and multicast levels to about 50 so ghosting is supported. If you have found more suffice levels please forward. Thanks Roger Just reading a bit here. A really nasty issue is when a single miniswitch or hub is looped on the hub itself and has only a single link to your switched fabric. BPDU Guard does not readily work here but a storm control of 20 will. We have also found a unicast level (like in the description above) set to about 30 will suffice and multicast levels to about 50 so ghosting is supported. If you have found more suffice levels please forward.

Thanks
Roger

]]> By: Aaron Conaway http://aconaway.com/2008/05/15/storm-control/comment-page-1/#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-page-1/#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-page-1/#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-page-1/#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-page-1/#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-page-1/#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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