IP phones not working

[Yenosh]

I have 3 cisco 8841 IP phones, These phones are showing unregistered in cucm.

I have verified these phones are coming up in switch and configured under voice vlan.

I can see three phones are receiving ip address, DHCP server is releasing the ip address . What could be the problem in this case.

[balaji.bandi]

At this stage we can only think of how these Phones contacting CUCM server to register?

Do you have DHCP Options  ? or how is your registration process ?

[Yenosh]

DHCP option is enabled and these phones are receiving different ip address when compared with other phones

[balaji.bandi]

Then check on the Switch VLAN Settings for that Access port where the Phones connected.

[Yenosh]

I just fixed one phone, by giving the IP address manually 

[George Sotiropoulos]

You need to check your DHCP settings as well as to verify if the Voice Vlan is distributed through the trunk on the switch that your phones are connected.

George

[balaji.bandi]

Glad it was working, suggest to check switch side helper address (if you have multiple DHCPservers in the network) and VLAN the Phone belong to.

[Yenosh]

I have verified dhcp server information and the phones are receiving IP address from correct dhcp server.

Please let me know how to troubleshoot further if phone is receiving IP address. 

[balaji.bandi]

What is the IP working Manually configured and tested. what is DHCP IP address you getting

can you post switch configuration to look.

[Yenosh]

IP Address which I manually enter is 172.27.192.51

Earlier it is receiving IP 172.27.192.15

DHCP pool  information 

network 172.27.192.0 255.255.255.192

interface cofnig

interface GigabitEthernet1/0/11

Switchport access vlan 10

switchport mode access

switchport voice vlan 30

no logging event link-status

srr-queue bandwidth share 10 10 60 20

queue-set 2

Priority-queue out

mls qos trust device cisco-phone

mls qos trust cos

spanning-tree portfast edge

spanning-tree portfast edge

service-policy input AutoQos-Police-CiscoPhone

End

[balaji.bandi]

IP Address which I manually enter is 172.27.192.51    <-- is this working ?

Earlier it is receiving IP 172.27.192.15   <-- if so this should also work because same range,

Do you have any FW or access rules ?

[Yenosh]

172.27.192.51 yes it is working, that's what I was wondering.

is there any way to get a logs from CUCM

[balaji.bandi · Accepted solution]

Troubleshoot IP Phone registration :

https://community.cisco.com/t5/collaboration-voice-and-video/troubleshooting-ip-phone-registration/ba-p/3103422