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VVX500 boot loop on Cisco switch, but boots fine on Extreme Switch

Occasional Advisor

VVX500 boot loop on Cisco switch, but boots fine on Extreme Switch

We have well over 200 VVX 500 phones in deployment.  We had one that begun a boot loop out of the blue.   That phone's since been replaced but I have the faulty one on my desk.  I was poking around and I can hit cancel on the starting application screen and factory reset it.  But even factory reset after starting application, the screen goes black and then all the lights come on and it starts the boot process over.  This was originally plugged into a Cisco 3750 switch stack in another building, but the same behavior happens plugged into a Cisco 3750 switch stack here in my building. 


Just for the heck of it I plugged it into an Extreme Networks 450G2 series poe switch and the phone boots up normally.  I verified that it obtained the proper voice IP address and the phone works.  Why would this single phone only work in an Extreme Networks switch?  We have at least 199 other phones that work fine in either.


When it boots up on the Extreme switch though it does show a warning - Rear USB port is disabled temporarily.  Detach the USB device and reboot the phone.  I can tap on OK to make this go away.  However there is NOTHING plugged into the rear USB ports.  Why would it say that?

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Polycom Employee & Community Manager

Re: VVX500 boot loop on Cisco switch, but boots fine on Extreme Switch

Hello @kjstech ,

welcome back to the Poly community.

Some or a couple of your old post(s) or reply(s) to them => here <= are still open/pending as you have not marked these as "Accept as a solution" or at least provide some form of feedback or answer.

If they are in this state nobody finding them via a community search will know if an answer or advice provided was useful and has maybe helped you.

Could you therefore kindly go over them and mark or answer as appropriate?

If they are marked as "Accept as a solution" other users can find these easier and it helps them to utilise the community more efficiently.


Please do not simply mark them without any type of feedback.

For your new issue:

Both the communities Must Read First and the FAQ reference the basic minimum information a new or follow up post should contain.

This ensures the questions having to be asked are limited and any new or follow up post contains the right amount of details to ensure any voluntary participant within the community does not spend additional time chasing basic information.

As a reminder the basic information asked for:


  • Provide the exact Software Version of your Phone
  • Provide the Phone Model
  • Provide the Call Platform (aka openSIP,Teams, Skype for Business Online, Skype for Business on Premise, Lync)
  • Provide details if UC / SIP or ObiEdition
  • Additional Poly Infrastructure (RPRM,PDMS or BToE)
  • If applicable provide a backup of the phone in question

UC Software 4.0.0 or later via the Web Interface Utilities > Phone Backup & Restore > Phone Backup > Phone Backup. Please rename into .TXT or Zip the file to attach.
Since UC Software 5.9.0 simply provide this via the Web Interface Diagnostics > Download Support Information Package

  • If possible provide a Log and either attach them or use the Code Tag.Consult the Troubleshooting Section found within the FAQ if applicable
  • If possible provide the MAC Address or Serial of the device
  • Provide details for example if the issue is a day 1 issue or only happened after an upgrade or any other relevant details
  • For questions around Support please check here


Whilst providing some of these details may not directly impact any possible answer the community can provide, it does enable Poly to have an overview of the current software used. In addition, providing all details at the same time allow us to check logs or look up potential support partners if an issue needs to come into support. It also enables us to verify the entitlement for using features.


Please ensure you always check the FAQ's and/or utilize the community search before posting any new topics or follow up posts.


We would need to get this into support.

In order to raise a support ticket, you need to work with your Poly reseller as they may need to do this for you.

End Customers are usually unable to open a ticket directly with Poly support.

If this is some sort of an Internet discounter providing your MAC address or your Poly devices serial will enable us to look up who would be able to support you. This may not be who you purchased the Poly device from.

If the unit is no longer within the warranty please be prepared to Pay Per Incident / PPI. This is all outlined in detail here

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.


Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
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