Setting up IP Phones not working with DHCP

[Lizzu]

Hello everyone.

I am having trouble configuring IP phones with DHCP. Even though I have the pool and I can assign IPs via DHCP for all other VLANs, it seems that something is not working correctly in the case of VLAN-40, which is the one of the phones. I made all configurations but it doesn't seem to work. 

I would appreciate some help on the matter, thank you for your attention, have a nice day

[Enes Simnica]

hello man. When troubleshooting VoIP DHCP issues for vlans and stuff, there are a few critical areas to verify: first, ensure the switch port connected to the DHCP server is properly configured as a trunk and allows VLAN 40 traffic. A common oversight is missing the voice vlan in the trunk’s allowed VLAN list. so use #show inter trunk on the switch to confirm voice or voip vlan is included. If it’s missing, add it with: int g/.... and switcpo tru allo vla add ...

the other thing is to check the dhcp relay on the router interfacing with the voip vlan, and fo so the router must forward dhcp requests to the server using the well known ip helper-add/, use some show commands to verify that.

u need to be sure that ur voice vlan exists globally on all relevant switches and that the phone ports are assinged the correct voice vlan..... The other thing (Lol) is to check the dhcp server scope for voice vlan..

would love to check the lab but im using my lunch break to answer/ ur question, so maybe later loool. 

have fun G, and hope it helps....

-Enes