will there be a flap if we configure a port to spanning tree port fast ?

[pcclonescisco]

I have a server connected to a access port with a default config and its in production. Right now, i want to configure that port to "spanning tree port fast".

will there be any flap/packet drop if i configure to port fast ? QUICK RESPONSE WILL BE HELPFUL.

[nathanaelminesso]

Hi Vikneswaran,

The port should not flap after Spanning-Tree Portfast has been enabled (if everything else is fine). You will see the usual warning like the one below

Warning: Spantree port fast start should only be enabled on ports connected

to a single host.  Connecting hubs, concentrators, switches, bridges, etc. to

a fast start port can cause temporary spanning tree loops.  Use with caution.

To be sure you can simulate it quickly with Packettracer.

I hope this helps.

Nate

[pcclonescisco]

Thanks for the update.

My question is, will there be any flap if the port is active and we are configuring to port fast ?

Let me try with packettracer as wel.

[nathanaelminesso]

Not if everything else is configured properly and the layout is the one you described me. I still recommend you to verify it quickly.

[handoko wiyanto]

perhaps you can give the copy of show tech-support command first, so that we can see the switch current state of spanning tree

but if you in a critical time, is there any port available on the current switch to do the testing