Basic question on 802.1w, "disabled" port

[news2010a]

From reading the documentation, I see that "disabled, listening and learning" port states from 802.1D became "Discarding" in RSTP.

That said, what happens if one goes to a switch in which I am running rstp and admin disabled one port. Isn't that port on "disabled" state? Or such admin disabled port is going to be considerd as "discarding" from the RSTP perspective?

[deyadav · Accepted solution]

Disabled port state, is the port which is admin down status, however a possibility to participate in STP if enabled.

The difference is only how it defined, so Admin Down port is referred as Discarding in RSTP. In discarding state, port would not learn any MAC address.

Hope this answers your question.

[news2010a]

OK, so if I understand this right:

The definition of "disabled" in RSTP is that it is part of the "discarding" state. That is how I have to see it.

Thanks!

[deyadav]

That is correct. Disabled/Discarding is the same thing. The port in this admin down status would not even hear BPDU's.

Other port roles, like Blocking and Listening, also referred as Discarding, would see BPDU's, however no MAC learning.

The common element between Blocking, Disabled and learning, is no MAC learning on that port, so traffic forwarding.

[Mohamed Sobair]

Hi,

First some comment on your previous paragraph.

The STP 802.1d port states are:

1- disabled

2- blocking

3- listining

4- learning

5- forwarding

The port states in RSTP has been changed to be as follows:

1- discarding

2- learning

3- forwarding

So, disabled, blocking and listining in STP 802.1d became discarding in 802.1 w RSTP.

The Disabled port states is the state of the port if its administratively down.

from RSTP prespective, all ports in STP 802.1d which are in , disabled , blocking and listining states are considered to be in discarding state from RSTP prespective.

HTH

Mohamed