VTP pruning not changing

[dirar]

Hello,

My VTP server is running, when I add a new vlan it gets added to all client switches. But when enabling or disabling vtp pruning it doen't get propagated or values do not change on domain switches. Any idea why this is happening?

VTP Server: 4500x

VTP Clients: 2960x

Thanks

[paul driver]

Hello

what vtp version are you running, are you using the same domain? -
When you mention vtp pruning do you mean pruning dynamically or manually?

Note: once you enable it globally dynamically you cannot then disable it globally it needs to be removed manually from each device and also some vlans are not able to be pruned ( vlan1, 1002 + )

[dirar]

Hello,

I'm using VTP version 3. Vlans are working well, but when I globally enable it, it doesn't work. "sh vtp stat" still showing different values on domain switches

[paul driver]

Hello

Okay in ver 3 you need to enable pruning on each switch individually it isnt proper gated through the vtp domain like in ver 1-2

Is your vtp server also the vtp primary if so just force an update from the vtp primary

vtp primary force

[dirar]

didn't know it's there is an issue with VTP v3. I can managed to do it manually, but I needed to know it's not an issue with the VTP setup.

Thank you

[paul driver · Accepted solution]

Hello

as long all your switches are compatible for  the vtp version your running then all should be okay 

note - vtp version 1 and 2 are NOT compatible with each other.

[Mehdi.a.majid1]

Hi, 

I have the same Question, But I think that since you are using the VTP v3 then you cannot just issue the #vtp pruning on the Primary-server-VTP and being able to propagate the pruning state to the other VTP v3 SWs in your VTP-Domain, 

and I think that the reason is :

VLAN Pruning

A pruning mechanism has been implemented into VLAN Trunk Protocol (VTP) to optimize the available bandwidth on trunks. As with both earlier VTP versions, pruning is available with VTP version 3 for the first 1k VLANs except VLAN1.

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-6500-series-switches/solution_guide_c78_508010.html

If my conclusion is wrong please correct me anyone.