Does portfast disable Spanning-Tree?

This topic is to discuss the following lesson:

Hi Rene,

I realized when you show
SW1#show spanning-tree interface FastEthernet 0/24 detail

q1) The “bpdu receive” is 0 - why ? ( non-root bridges do not send bpdu to root bridge ?)

q2) What is the difference between “P2P Edge” and “P2P” ? What do that actually meant ?

q3) Do we use portfast on ports that we are sure will not cause a loop ?

Regards,
Alan

Hi Alan,

  1. With PVST, BPDUs are relayed from the root bridges down the tree to other non-root bridges.
  2. P2P Edge means that portfast has been enabled. Portfast enabled interfaces don't trigger a TCN. Take a look at the portfast tutorial here, I explained it there.
  3. That's right, Cisco IOS warns you when you enable it on interfaces. It doesn't disable STP though so it's not like you will have permanent loops.

Rene