Phones Stuck at Initializing DNS

[h2safetyservices]

I have Cisco IP phones connected to a Cisco SG300-52MP switch

All of our Cisco IP phones stopped working around 10AM today with orange lights on the line buttons. All of the phones are plugged into the Cisco switch. I tried rebooting the phones. When I do that they get to a screen that says “Initializing DNS” and don’t go any further. I can plug the phone into another switch and things work perfectly, which makes me think there is definitely something wrong with the switch. I don’t have a lot of experience with Cisco switches and IP phones so I'm hoping someone can give me a hand troubleshooting this. I have tried rebooting the switch, but the problem persists. Any help is much appreciated.

[sathvik k v]

Hello,

 If you have access to the switch check the interface status connected to IP phones.Which seris ofswitch is the IP phones connected to? Can you try connecting the IP phones to other modules of a switch

Regards,

Sathvik

[h2safetyservices]

I'm not sure what you mean be "series". It's a Cisco SG300-52MP. It does not matter which port I connect to; I get the same result. As I mentioned in my comment, I can connect to a different switch and the problem is resolved.

[sathvik k v]

Is this the only IP phone on the switch which is not working? On which series of switch are you trying to connect.

[Sam004]

I was also encountering this problem.

In the admin section, under the advanced section

Proxy and Registration

I found these parameters set to no.

Changed to yes

Use DNS SRV:

DNS SRV Auto Prefix:

Also added SIP proxy URL and set Use Outbound Proxy  to yes

Outbound Proxy:  [added SIP URL]

 
Use Outbound Proxy: [changed to yes]