Specific Cisco VTP Pruning question(s)

I've never bothered with VTP and we're mostly Procurve anyway, but does VTP use spanning tree at all? I don't think spanning tree is really used at all in VTP, so looking at spanning tree isn't going to tell you anything useful. I think "sh vtp status" would have more pertinent information. Also certain VLANs (>1005) are ineligible for pruning, so perhaps move your wireless backbone to a new VLAN ID in that range? --------------------------------------------------------------------------------------- Gavin Pyle | Network Engineer | Green River Community College gpyle@greenriver.edu Breathe easy - Green River is now tobacco-free!

It shouldn't. Down stream switches should advertise the use of VLANs to to their neighbors through VTP to prevent upstream switches from pruning the links.
Heath Barnhart, CCNA ITS Network Administrator Washburn University Topeka, KS
On 01/18/2013 04:56 PM, Dennis Bohn wrote:

HI Peter,

Just had another thought.  I wonder if in a VTP domain there were a switch (Switch A) with a given VLAN, say 665 configured via VTP.  And if the switch had no access ports configured on port 665, but was trunking to a downstream switch that DID have access ports on vlan 665.  Would VTP pruning prune that vlan 665 from Switch A?  I don't know but think it is possible.   Might be worth an experiment.  The other thing is, were all switches in VTP server mode or were some in client or transparent?  

best,

dennis

Dennis Bohn
Manager of Network and Systems
Adelphi University
bohn@adelphi.edu
5168773327

So I understand it, your network is CoreNetwork>Additional Segments>Cisco Switch>UbiquityStation>BuildingNetwork, correct? I'm not familiar with that product, but a quick Google search is telling me that its a wireless bridge? Does VTP normally get passed across the bridge? If not, then I suspect what happened was that the switches across the link weren't able to communicate their VLAN usage across the link, or the the VTP message was lost in transit. In which I believe VTP would on the switch connecting to the Ubiquity would prune the VLAN. Heath Barnhart, CCNA ITS Network Administrator Washburn University Topeka, KS On 01/18/2013 06:25 AM, Peter Charbonneau wrote: > Good morning, > > At a network low utilization period this morning, I turned on VTP Pruning in our Nexus core. > > Immediately, we lost all of our Ubiquity bridges and the buildings tied to them. From a Layer 2 perspective, all of the devices attached to the switches, where the base stations are located, still showed up as CDP neighbors, but the Layer 3 "stuff" was not working. > > Our Ubiquity base stations are attached to switches as trunk ports, and we have BPDU filtering turned on. > > When I showed VTP status on the switch, it did show pruning enabled, but in looking at the specific VLAN in Spanning Tree, everything looked fine. > > Does anyone have any light that they could potentially shed on this? > Does anyone have any insight on how to troubleshoot this? > > I think it would be futile to create a Cisco TAC case for this, but **SHRUG** > > > PeteC > > > Peter Charbonneau > Sr. Network and Systems Administrator > Williams College > (413) 597-3408 (office) > (413) 822-2922 (cell) > OIT will NEVER ask for your password! > > ********** > Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. > ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.