Configuring Catalyst 2950

Unanswered Question
Jul 28th, 2006
User Badges:

Hi Collegue,

My CallManager and ip phones are in placed.

I have a Catalyst 2950 ONLY available in my lab.

CallManager and IP phones are attached to my 2950. DHCP server is also configured in my Callmanager.

If I attached my IP phones how can I configure my 2950 to get the IP address in my call manager.

Please be advised.


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 3 (1 ratings)
Bobby Thekkekandam Fri, 07/28/2006 - 06:54
User Badges:
  • Cisco Employee,


Are you asking how you can configure the 2950 to receive a DHCP address from the callmanage?



royalblues Fri, 07/28/2006 - 08:00
User Badges:
  • Green, 3000 points or more


THere is no configuration required on the 2950.

I assume that your IP phones and Call Manager are in common IP schema.

Just plug the phones and they should be getting the IP

However if you want the Auxillary VLAN feature .e connecting a phone and PC to the same port you ahve to configure voice vlan

eg (data =vlan 2 and voice =vlan 3)

(config)#switchport access vlan 2

(config)#switchport voice vlan 3



JUNKSA_2 Fri, 07/28/2006 - 11:41
User Badges:

Hi Narayan,

see the config:

interface vlan 20

ip address

ip helper-address

no shut

config#interface fastethernet 0/17

config#switchport access vlan 20

config#spanning tree-portfast


I try this configuration but nothing happen. Do I missed any configuration or the configuration is wrong?

Please be advised.


JUNKSA_2 Fri, 07/28/2006 - 11:30
User Badges:

Hi Bobby,

Yes,I already configured the CallManager and I also run the DHCP server on the same machine.

I dont understand why all the IP phones is not getting any IP from the DHCP.

The CallManager and the IP Phones are attached in the same 2950 switch.

I created vlan 20 (Voice) see the configuration below:

interface vlan 20

ip address

ip helper-address

no shut

interface vlan1

no ip address


**** port 1 and 2 are my call manager servers

**** port 17 to port 20 are the IP Phones

see the configuration for the port:

interface fastethernet 0/17

switchport access vlan 20

spanning tree portfast

I dont know if there is something missing or wrong in my configuration.

Can you help me to sort it out the problem.


globalnettech Fri, 07/28/2006 - 11:57
User Badges:
  • Silver, 250 points or more


sorry for the confusion: the 2950 cannot do any layer 3 routing, so your VLAN 20 interface is for management only. Which VLAN are the call manager servers in ? If you have only the 2950, put all devices/switchports in the same VLAN.

Can you post the entire configuration of your 2950 ?



JUNKSA_2 Fri, 07/28/2006 - 20:48
User Badges:


You are right I was totally confused, I know that 2950 is a layer 2 switch only and cannot do routing.

I put all the devices in the same vlan without any configuration in the switchport and it works.

Thanks for the advise.


This Discussion