[Bridge] how bridge do the state transfer from learing to forwarding

Chris Healy cphealy at gmail.com
Tue Apr 15 02:18:27 UTC 2014


1) The initial state of a port if it is running STP is disabled.  Once
there is link, it will transition to blocking.  After that point, depending
on the state of the rest of the network, it will either stay blocking or
attempt to transition to forwarding.

2) If a port state is in learning, that means that the bridge has
determined that it is OK for the port to go to forwarding, but it has not
been in the learning state for a long enough period of time. (learning is a
transitionary time period in the STP when a port will learn mac addresses
but will not forward traffic.)  Provided there is no topology change that
would result in the logic taking the port back to disabled, the local port
state should go from learning to forwarding after 1x the forward delay.
(This assumes the link does not go down, in which case the port state will
go to disabled.)

Hope that helps,

Chris


On Mon, Apr 14, 2014 at 7:08 PM, longguang.yue <kernelluck at 163.com> wrote:

> hi,all
> 1.
> if the initial state of port is learning?
>
> 2.
> in what case, state trandfers from learing to forwarding, what is the
> condition?
>
>
> thanks
>
>
>
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