cisco 7941 G IP Phone VLAN Communication problem

[pradeepkum]

We are facing problem in Cisco IP Phones 7941 G in Vlan Communication,

We are having 2 Vlans for IP Phones Vlan 97 and Vlan 100, problem is, few IP Phones which are currently on static IP's are not working over Vlan 97, when we configure them for DHCP (Yes), but working in Vlan 100 with DHCP (Yes).

As well as when we connect any other working Ip phone over the same LAN point in Vlan 97, its working fine whether its is new Ip Phone, any other existing Vlan 97 phone or Vlan 100 Ip phone.

I m unable to rectify the problem.

SO I request U kindly suggest sollution............

[nitsinha]

Hi Pradeep,

By "not working" in vlan 97 do you mean that the IP phones do not get an IP address from DHCP in vlan97 or they get an IP but can't register to the TFTP server there? What error do you see on the non-working phones?

Regards

Nitesh

[pradeepkum]

Dear Nitesh,

I mean to say that IP phone is not taking IP addresses from DHCP server in Vlan 97, but able to take IP address in Vlan 100,

and, also any other Ip phone on the same point is able to get Ip address from DHCP server in Vlan 97.

regrads

Pradeep

[nitsinha]

Hi Pradeep,

Since these phones never took the IP address from vlan 97, it is quite possible that it has the IP of the other vlan. Did you try erasing the network related settings(IP,subnet mask etc.) and rebooting the phone? If not, try and let me know

HTH

Regards

Nitesh

PS:Pl rate helpful posts

[pradeepkum]

Hi Nitesh,

IP phone made to factory default but still having the same problme, other phones are taking Ip addresses in the same Vlan 97.

regards

Pradeep

[nitsinha]

Hi Pradeep,

So u mean even after performing a factory reset, the IP phone is not releasing its old IP address? Which firmware is the IP phone running? CAn you try updating its firmware by connecting it to a different vlan?

Regards

Nitesh

[pradeepkum]

hi Nitesh,

Everything is done, firmware is upgraded 2 times but still have the same problem.....

regards

Pradeep

[nitsinha]

Hi Pradeep,

This issue looks weird.  Take packet(wireshark) captures from the non-working phone when its sending DHCP request to the DHCP server and check at which stage is the DHCP process failing. At this point, this is the best you can try.

HTH

Regards

Nitesh

[pradeepkum]

Dear Nitesh,

Already logs taken from wireshark is not showing that Ip phone int the logs.

This process was done by me so many times but still no logs found related to that faulty one and Othjer faulty ones too.

regrads

Pradeep              

[shabeebmohammed]

Dear,

From what i understand. (please correct me if im wrong)

Your using Cisco 7941G.
2 Vlans (voice) 97 and 100
IP Phone in vlan 97 - static (few only, remaining are DHCP)
IP Phone in vlan 100 - DHCP

now you configured these static phones for DHCP over vlan 97 and they are not working.. right???

a. please realese the ip from the phone
b. restart the phone.
c. if still no, then check if you have any remaining ip in the DHCP schema (i mean the non excluded range)

i beleive it will be "c". please check and keep us updated.

BR

Shabeeb

[pradeepkum]

Dera Shabeed,

can u please let me how to realese IP from Ip phone,

Everything is ok whatever u noticed.

regrads

Pradeep

[shabeebmohammed]

On the phone -

go to settings - network settings - select ip address release

it will be locked by default.. click * * # to unlock settings.

then click release and wait for some time..

restasrt the switch and see if your getting any ip.. else check the DHCP server also..

[pradeepkum]

Dear Shabeed,

This activity has done already and I just cannot restart the switch even the call manger also,

suggest me anything else apart from the resettig of switch.

regrads

Pradeep

[shabeebmohammed]

ooops.. my bad.. i meant restart the phone..

[pradeepkum]

Its ok dear