Spanning-tree rapid pvst question

[bram.a]

Hi,

I'm trying the following setup:

So I only want vlan 999 between Switch B and Switch C, but spanning tree is blocking vlan 999 on it's end. Since vlan 999 is not in the trunks between A&B and A&C and do not understand why it's blocked.

Can someone explain why and how to prevent it?

Thnx.

[MHM Cisco World]

you need to allow PVST or Rapid-PVST 
I seem to me you run STP (legacy)
MHM

[bram.a]

Might be some limitation within packet tracer (I'm trying to simulate first before putting it in prod.) but according to packet tracer: 

Spanning tree enabled protocol rstp

[MHM Cisco World]

if you apply
show spanning tree 
do you see STP for each VLAN ?
share the show spanning tree for three SW 
let me check it 
MHM

[bram.a]

Noticed a topic for packet tracer, that it would only work if the switch was reloaded.

Tried, and now all the links are up and it works as expected, thnx anyway!

[MHM Cisco World]

you are welcome 
I run packet tracer LAB for your case and it work, the only topic is make sure the VLAN is allow in trunk and STP mode is PVST

MHM

[r.tirado]

Hi MHM, thank you for your time. I solved my issue with a GRE Tunnel, EIGRP is UP an stable now. I took advantage of this, to implement ipsec encyption in order to protect my data.

Thank you for your time.

Roland

[MHM Cisco World]

Your are so welcome, 
I think my friend you answer in different post but anyway I am so glad your issue is solve 
have a nice day ALL
MHM