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
  • 5
  • 3
LVL 36

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 36

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

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.
How to run any project with ease

Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
- Combine task lists, docs, spreadsheets, and chat in one
- View and edit from mobile/offline
- Cut down on emails


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 36

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.

Featured Post

What Should I Do With This Threat Intelligence?

Are you wondering if you actually need threat intelligence? The answer is yes. We explain the basics for creating useful threat intelligence.

Join & Write a Comment

SSL is a very common protocol used these days when browsing the web.  The purpose is to provide security to communication, but how does it do it?  There are several pieces at work that have to be setup before SSL will even work and it requires both …
This is the first one of a series of articles I’ll be writing to address technical issues that are always referred to as network problems. The network boundaries have changed, therefore having an understanding of how each piece in the network  puzzl…
Viewers will learn how to properly install and use Secure Shell (SSH) to work on projects or homework remotely. Download Secure Shell: Follow basic installation instructions: Open Secure Shell and use "Quick Connect" to enter credentials includi…
After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

757 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

19 Experts available now in Live!

Get 1:1 Help Now