2950 AND IP PHONES-PC'S DO NOT HAVE CONNECTIVITY

[mschlenger]

Phones work...PC's don't....Any ideas? I add the PC to a static access port and I can ping everything. Same config on a 3550-24 works fine...weird....Oh, and the "switchport trunk encap dot1q" command is NOT available on this platform...even more weird....

Switch To Phone:

interface FastEthernet0/1

description IP phone and PC

switchport trunk native vlan 7

switchport mode trunk

switchport voice vlan 17

switchport priority extend cos 5

no ip address

!

Switch trunk to router:

interface FastEthernet0/12

description Trunk to 1760 router

switchport trunk native vlan 7

switchport mode trunk

no ip address

Router interface:

!

interface FastEthernet0/0

no ip address

speed auto

!

interface FastEthernet0/0.7

encapsulation dot1Q 7 native

ip address 192.168.7.254 255.255.255.0

!

interface FastEthernet0/0.17

encapsulation dot1Q 17

ip address 192.168.17.254 255.255.255.0

!

[konigl]

I have a 2950G-12 which works with IP Phones and PCs. All 10/100 ports are configured as VLAN trunk ports. IP Phones work on the voice VLAN, direct-connected PCs work on the native VLAN, and ports with IP Phones with PCs attached use both. Switch configuration was copied over from the 3524-PWR switches I have in every wiring closet. (This 2950 is the only non-powered one with IP Phones on it.)

I use the same commands as your "Switch to Phone" config on my 10/100 VLAN trunks, except I use "switchport priority extend cos 0" to make sure the inbound voice traffic on a port always gets priority over the PC's data traffic, whenever both an IP Phone and a PC are plugged into it. And I use "spanning-tree portfast" on the 10/100 trunk ports, to go straight from "no link" to forwarding.

I also have 2620 routers set up to do interVLAN routing using subinterfaces. The commands I'm using don't look any different than the ones you're using.

I don't see anything in your configs that sticks out like a sore thumb. What versions of IOS are you using on the router and switch?

As for the switchport encapsulation, if you create a VLAN trunk on a 2950 it's always going to use 802.1Q encapsulation. Cisco Catalyst 2950 Series does not support ISL trunking; and there are no plans to support it on that platform. Since encapsulation choice is not an option, there is no need for a command to specify one.

The Catalyst 3550 switches support both ISL and 802.1Q trunks, for those with a requirement to deploy ISL trunking.

Hope this helps.