what happen when a RSTP edge port receive BPDUs?

szokp

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tomaifauchai

shutdown because bpdu guard is enabled with portfast (Edge) by default

billyr

I think you should maybe lab this up. I'm pretty sure it doesn't error disable but just transitions to the normal port role.

tomaifauchai

billyr wrote: »

I think you should maybe lab this up. I'm pretty sure it doesn't error disable but just transitions to the normal port role.

According to this, you are right. Sorry!
I thought you would get the same behavior than 802.1D

https://learningnetwork.cisco.com/message/84416

szokp

billyr wrote: »

I think you should maybe lab this up. I'm pretty sure it doesn't error disable but just transitions to the normal port role.

what else action will the SW do besides turning the port to normal STP port ? sending BPDU with TC bit set ?

chmorin

szokp wrote: »

what else action will the SW do besides turning the port to normal STP port ? sending BPDU with TC bit set ?

What do you think happens, and why?

BroadcastStorm

This is riot

szokp

chmorin wrote: »

What do you think happens, and why?

when BPDU received form edge port, it means that the port connect a SW other than a host, the STP topology has changed actually，so TCN should be sent to notify other SW and root bridge to respond for that change。

APA

szokp wrote: »

when BPDU received form edge port, it means that the port connect a SW other than a host, the STP topology has changed actually，so TCN should be sent to notify other SW and root bridge to respond for that change。

With RSTP, when a BPDU is received on an edge port.... the port loses edge port status and thus becomes a normal port in the spanning-tree topology going through the Discarding -> Learning -> Forwarding stages.

szokp

APA wrote: »

With RSTP, when a BPDU is received on an edge port.... the port loses edge port status and thus becomes a normal port in the spanning-tree topology going through the Discarding -> Learning -> Forwarding stages.

according to this ,Not until the edge port finally turn into forwarding state, the TCN will be sent?

stuh84

That should be it, as TCNs in RSTP shouldn't be sent until it reaches the forwarding state.

APA

Spot on..... TCN only gets sent when the topology has converged.... thus meaning the port must be in forwarding state for a TCN to be sent.