We got a couple of SoundPoint 331, connected into LAN against one Cisco voip switch, who is giving DHCP to the phones with VLAN ID 20.
There's an intermediate step, another Cisco switch where all computers are connected, also the Domain Controller with DHCP services
So, when we connects a SoundPoint into the LAN, the phone is smashing the Windows dhcp, pushing out computers or printers that catches the IP from the Domain Controller.
In the intermediate Cisco switch, I've already configured the port where the Domain Controller is connected to deny the VLAN 20, so I don't know how to configure the telephone to work only with the VLAN 20 and the DHCP from the Cisco VoIP switch.
It's some kind of DHCP storming or something and I really don't know how to resolve it.
welcome to the Polycom Community.
It is always useful to include the currently used software version as issues experienced may already be addressed in a newer release.
This also allows yourself and others to check against current software release notes.
Therefore the Polycom VoIP FAQ contains this post here:
Question: How can I find out my SIP UC Software Version or the BootROM Version of my Phone?
Resolution: Please check here
In order to answer your VLAN question the community's VoIP FAQ contains this post here:
Jul 10, 2013 Question: How can I use VLAN's with Polycom phones?
Resolution: Please check => here <=
Above issue sounds like a switch configuration issue as the Phone in factory default simply sends out a DHCP Discover in a native LAN aka no vlan.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Polycom Global Services
If official support is required please check how to phone or open a case here----------------