VLAN not trunking between cat2900xl and 2950

[ibrunello]

Strange behaviour.

I have a cat2900xl and a 2950.

Just set VTP on both.

Interface are trunked in 802.1q on both (explicitly set on 2900xl, since by default it uses ISL).

Native VLAN is 1 on both.

Create VLANs on 2950 (which happens to be the VTP server), and they're connectly seen on the 2900xl.

Set VTP version 2, and both run in v2-mode.

Set pruning, and both set pruning.

create vlan4, and it's showed on both.

set an access port on vlan 4 on both, and traffic is not forwarded.

("show vlan" on 2900xl correctly shows the interface associated to vlan4).

notably, vlan4 is pruned on 2950 uplink interface (show interface trunk).

any hint?

TIA

Ivan

[Yudong Wu]

can you post your config with "show interface trunk", "show vlan" and "show spanning-tree vlan 4 summ".

[ibrunello]

sorry for the delay (being GMT+1, whole weekend passed).

neither "show interface trunk" nor "show spanning-tree vlan 4 summ" is supported on cat2900xl. Including "show spanning-tree vlan 4", hoping this may suffice.

Ivan

[Yudong Wu]

Hi Ivan,

Can you make sure all related ports are in up/up state and capture "show spanning-tree vlan 4 detail" on both switches and "show interface trunk" on 2950?

Please post the related configuration as well, such as VTP config and port/trunk config.

[ibrunello]

I cannot run right now, since, due to service delivery, I have to move all devices currently running in vlan 4 into 2950.

Gonna wait till tomorrow, so I can find a suitable remote machines (it's a couple of miles away from here) connected to 2900xl, so I can move it to vlan 4, just to see what's changing, and give you the relevant show's output.

[Mohamed Sobair]

VTP prunning eleminate unneccessary broadcast requests from a Switch.

You have VTP configured, what is the VTP mode on both Switches? pls post sh int trunk from both?

HTH

Mohamed

[ibrunello]

show int trunk does not work on c2900xl.

For the output, see the attachment above

[Leo Laohoo]

"sh interface status" will work.

[ibrunello]

you're right.

r-mi-ds69#sh int status

Port Name Status Vlan Duplex Speed Type

------- ------------------ ------------ -------- ------ ------- ----

Fa0/22 r-mi-ds70 f0/1 connected trunk A-Full A-100 100BaseTX/FX

[ibrunello]

VTP is server on 2950 and client on 2900xl

[ibrunello]

another info:

2950 is running rapid-pvst+, meanwhile 2900xl is running vanillca pvst.

This never gave a problem, since usually the rapid downscales the port to shared

(right now trunk port is seen as "P2p Peer(STP)")

[glen.grant]

Can you post the trunk setup info for the 2900xl on the connecting port? If you can't ping between them then the trunk isn't working right.

[Leo Laohoo]

Can you post the config for both the 2900XL and 2950 trunk ports?

[ibrunello]

sorry for the delay.

here they are.

cat2900xl#sh run int f0/22

Building configuration...

Current configuration:

!

interface FastEthernet0/22

description cat2950 f0/1

switchport trunk encapsulation dot1q

switchport mode trunk

end

cat2950#sh run int f0/1

Building configuration...

Current configuration : 85 bytes

!

interface FastEthernet0/1

description cat2900xl f0/22

switchport mode trunk

end

[Leo Laohoo]

What VLAN IP Address on the switches are you trying to ping? Is this enabled? (Note: You can only enable ONE VLAN in the 2900/3500XL and 2950).

On the 2950, can you type and post the following commands:

sh int f0/1 status

sh int trunk

sh int f0/1 switchport

On the 2900, can you type and post the following commands:

sh int f0/22 status

sh int f0/22 capab