ShoreTel phones - show NO SERVICE - ShoreTel supports says its a network problem

Posted on 2013-01-15
Last Modified: 2013-04-02
I have a ShoreTel installation that is having something really strange happen. On a regular basis, the phones suddenly go to No Service. These are phones that have connected to the ShoreTel switches for resources all ready. We talked with ShoreTel support and they say that there is a networking problem that is causing the phones to lock up. Once a reboot of the phone (unplug & plug in) happens, they are fine for a couple of days. Some lock up more than others. I have looked at the logs on the switches and the only real activity I see in them is STP enabling and disabling the ports. Most ports happen once a day but some are happening often. Let me know if you would like to see any logs and I'll post them.

Thanks ahead of time.
Question by:bundydoc
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LVL 37

Expert Comment

ID: 38782068
There should be no need to STP to be changed on the ports, this would indicate that something is not working correctly, possibly a L2 loop somewhere ?

A copy of the HP config would be useful.

Author Comment

ID: 38812250
I am attaching a copy of the Core switch. It is a fairly large deployment with 3 HP 5412s, 2 HP 2910, and 4 Cisco 3750 switches (at this site). If it would help to see any of the other configs, I can attach those too.
LVL 37

Expert Comment

ID: 38812316
I'd go with something on the phones causing a loop which then activates STP and shuts down the port.

Just posting a telnet/ssh log with "-- MORE --, next page: Space, next line: Enter, quit: Control-C" isn't ideal.

I generally find it simpler to use tftp to copy configs off, however I see that you have it disabled. As an alternative, there is the web interface which can display the config.

Realistically however in a network such as yours, you should at bare minimum be running rancid, if only to log configuration changes...

I'd suggest that you used syslog to copy the logs from the server, and then monitored the phones to see if you can tie the phone "No Service" to the port that the phone is on blocking due to STP.

I would also setup a monitor port going to a packet sniffer with a lot of disk space, you should be able to confirm why the port is blocking due to STP
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Author Comment

ID: 38860809
ArneLovius - thanks for the reply. What I don't understand is that this isn't just happening on one of the switches or the same phones. It seems to be totally random and is spread out over the 5 switches at the site.

Author Comment

ID: 38967140
It looks like there is a problem with the broadcasts. We think it may be on the DATA VLAN (default) and not the voice. We are going to separate the site into multiple Voice VLANS to see if we can isolate the problem further.
LVL 37

Expert Comment

ID: 38968025
you'd need a LOT of broadcast traffic to stop the phones from being able to connect, enough to trigger warning messages on the HP switches...

Accepted Solution

bundydoc earned 0 total points
ID: 39029339
So far we have separated the different departments into their own VLANs and the problem has gone away.

Author Closing Comment

ID: 39039748
We didn't really find the "cause" of the lock ups but we found a solution.

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