WS-C2960C 8-TC-S switch and VTP

[codflanglers]

Was hoping someone could help me here.

We have just purchased a large number of these to provide edge access to lecturns.

The uplink switch ports are configured as trunks (as are the switches they connect to). VTP mode is set to client.

The first couple went in fine and picked up vlans as expected (the switches themselves only need 4 vlans plus the defaults and support 64).

However, we plugged some in yesterday and they keep resetting back to VTP transparent mode with the following error

%SW_VLAN-6-VTP_MODE_CHANGE: VLAN manager changing device mode from CLIENT to TRANSPARENT.

Now according to Cisco it is either due to number of vlans supported (not the case as we use the switchport trunk allowed vlans command to limit the number of vlans being transmitted to these switches).

Or it could be the number of spanning-tree sessions per vlans....but again we limit the number of vlans to 4 incoming so I don't think thats it. Plus we do have some of these switches working and they are showing about 50 vlans ok.

Any suggestions? Known issues? Currently running 12.2(55)EX3

[Rolf Fischer]

Hi,

Now according to Cisco it is either due to number of vlans supported (not the case as we use the switchport trunk allowed vlans command to limit the number of vlans being transmitted to these switches).

with manual pruning  you can limit the number of STP instances but it has no effect in synchronizing the VLAN database. The content of the VTP server's VLAN database will completely be distributed among the clients.

Do you have more than 64 VLANs in your VTP-domain?

Best regards

Rolf

[codflanglers]

There are 70 vlans in the VTP domain yes

[Rolf Fischer]

Well, in this case the switch behaved like expected.

If you have only a few number of VLANs and the VLAN-config doesn't change very often, you could just leave it in transparent mode.

I think with a different licence 128 VLANs are supported (if you want to use VTP distribution) but I've to do some research on that.

Best regards

Rolf

[codflanglers]

Yeah, we managed to get things working with transparent by adding the vlans in manually

[Rolf Fischer]

As far as I can see, the 2960C-8TC-S comes with LAN Lite and an upgrade to LAN Base is not posible (Table 9):

http://www.cisco.com/en/US/prod/collateral/switches/ps11527/ps11289/qa_c67-650819_ps11290_Products_Q_and_A_Item.html