Poly CCX-350 telephones not getting correct subnet mask

[CCX_User]

We have purchased Poly CCX-350 handsets to use on Teams and they work on our Extreme network when they use statically assigned IP addresses, mask and gateway but do not get the correct the subnet mask when DHCP is set. We get the following.

000035.828|cfg |*|00|RT| Phone IP address is 10.168.32.107.
000035.828|cfg |*|00|RT| Subnet mask is 0.0.0.2.
000035.828|cfg |*|00|RT| Gateway address is 10.168.32.1.

or

000103.869|cfg |*|00|RT|Primary IP: 10.168.32.107 subnet mask 255.0.0.0

The subnet mask should be 255.255.248.0

We have upgraded the software to

Software Version

8.1.6.1006

Our network is a /21 network, not sure if that causes a problem.

Any assistance would be appreciated

[SteffenBaierUK]

Hello @CCX_User ,

welcome to the HP Poly community.

From our general VoIP FAQ:

Aug 24, 2015 Question:What basic network data is sent and received by a Poly phone?

Resolution: Please check this post => here <=

Most likely the phone is picking up random Sub Option 43 that it tries to interpret and therefore gets the Subnet wrong.

This is of course an assumption and opening a case with our support organization would be the correct next step.

Best Regards

Steffen Baier