AP 370s all lose WAN/LAN connectivity at same time, go amber and can't obtain IP.

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I'm in a very standard and simple Windows 2008 AD environment. DNS, DHCP handled by our domain controller. The AP 370s are powered via PoE. I have 2x Dell Powerconnect 5548P switches that provide PoE. I have enabled "storm control" on the Dell switches. (as I have suspected this may be the culprit and unrelated to the APs).

I have had these APs for several months now and have had very minimal issues. This seemed to start out of nowhere and I assumed broadcast storms were the culprit. It happened last Friday, and again today (the following tuesday.) The really frustrating part is that after I made changes to our main Dell switches (all traffic flows through these.) The problem went away for about a month... AHH!

So my solution at this point has been to power cycle our PoE switches, this works 100% of the time. The next time this happens I'm planning to manually unplug the APs, leaving the PoE switches powered up.

A few things to note:
-Wireless becomes useless when this happens. Packet loss is almost 100%
-Folks that are hardwired into the network can still ping across the LAN/WAN but with an increase in packet loss (maybe 10%).
-Attempting to connect to a server with RDP, SMB, access the Dell switch GUI via web, etc. usually times out or will load an extremely small amount of the website.

Please help.
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Jared Koreski

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Posted 4 years ago

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Andrew MacTaggart, Champ

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If the AP is not getting an IP, most likely the storm control is preventing the DHCP broadcast frames from reaching the DHCP servers.

what percentage or bandwidth did you set?

console(config)# interface gigabitethernet 1/0/1 

console(config-if)# storm-control broadcast level kbps 12345

I would say you should not need this if the network is segmented properly.

are you using 1 or 2 interfaces on the 370?


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Jared Koreski

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I'm using 1 interface on the 370s, assuming you're talking about ethernet interfaces.  Yesterday I found a rogue 5 port linksys hub hiding under a conference room desk throwing packet errors at our PoE switches.  No other ports reported any errors except this one.  It has been removed.  I'm hoping that was the culprit.  I have searched this office high and low for rogue devices and an ethernet cable plugged back into itself.  Can't find anything.
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Jackywong

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J. Goodnough, Champ

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Have you looked for other switching loops in your network topology? The APs losing connectivity may just be another symptom and not the source.
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Kurt Kidder

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Hi Jared,  I may be stating the obvious, but here goes.  Have you disconnected each switch uplink one at a time to see if you can tell if the problem is originating from one switch or the other?  I had this happen at a school I support and we found the source switch then started unplugging each individual cable until the "issue" stopped.  Just saying you may be able to narrow it down if it turns out to be unrelated to the switch.  Turns out that one teacher had both ends of a cat 5 plugged into a classroom switch.

Good luck,
Kurt
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BJ, Champ

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Does HP have a BPDU guarding mechanism?
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BJ, Champ

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This link may help...
http://evilrouters.net/2009/03/11/bpdu-protection-on-hp-procurve-switches/

Of course enable BPDUs on the ports that you know are connected to other switches. What type of STP are you running? Make sure you have a centralized switch designated as the root.  
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Jared Koreski

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Kurt, we've got a very small office (50 people)  I have looked in every nook and cranny for any hubs and removed all them except one that sits right next to me for the printers.  A very very small amount of people have hard lines to their computers and I've checked every ethernet jack in the entire office for physical loopbacks.
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Jared Koreski

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BJ, I'm running Rapid STP on 2 Dell PowerConnect 5548P switches that are mastered/slaved together with an HDMI backbone.  There are no BPDU settings for the HDMI ports that I know of.