CCX 600 DHCP Fails

[Anonymous]

I am having trouble with Microsoft DHCP and our CCX 600.  The phone is connected to a Fortiswitch running LLDP and attempting to obtain an IP address via DHCP helper from a Microsoft DHCP server in a neighboring subnet.  Wireshark shows me DHCP discovers and DHCP offers but apparently the CCX is not accepting the offer.  I am testing two CCX 600's.  I upgraded one to the latest firmware version and it did not appear to make a difference.  I pivoted to a DHCP server configured on the Fortiswitch and I still cannot get the phones to accept an IP.  Any insight would be helpful.

[SteffenBaierUK]

Hello @AlexKS ,

Stating the latest software does not help others when finding this post in days, weeks, months, or years to come as they do not know what software mentioned was current at the time of writing.

Please therefore always post the exact complete build id and in the case of Microsoft Teams all the details about the Teams IP phone and the Admin Agent, Company Portal, and Partner Agent. Our Partner Microsoft has the ability to upgrade the software of their applications so it is important to know what is being used and not what is part of our firmware

Therefore the Poly VoIP FAQ contains this post here:

Question: How can I find out my SIP or UC Software Version of my Phone?
Resolution: Please check here

For your actual issue also from our "normal" VoIP FAQ:

Jul 31, 2020 Question: How can I troubleshoot a phone not getting an IP or DHCP issues?

Resolution: Try a manual IP => here <= or for DHCP logging check >here< and check LLDP or CDP => here <=

If you are unable to do this please contact our Support organisation in your region.

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

Best Regards

Steffen Baier