Re: STP and RSTP congergence time

On 5月14日, 上午9时52分, Albert Manfredi <bert22...@xxxxxxxxxxx> wrote:
On May 13, 6:48 pm, aaabb...@xxxxxxxxxxx wrote:



"RSTP can very quickly jump from discard to forwarding, if it receives
the appropriate BPDU from another switch. Two switches can propose and
agree with one another, without having to wait, listen, and learn."

You meant that it can happend during from power up to stable stage?
before I think it only happen after link failed then go to stable
stage.

From power up, or after a configuration change, it makes no
difference. RSTP does not depend on the timers timing out, as STP
does. RSTP instead works from the BPDUs of neighboring switches
immediately. STP is very conservative, working to prevent loops and to
prevent duplicate or misordered frames. Topology updates propagate
throughout the spanning tree before frames are forwarded. RSTP instead
does not wait, even if this risks the potential for duplicate or
misordered frames.

The timers established in RSTP are mainly for backward compatibility
with STP, in case some switches in the spanning tree are only STP-
capable. Other than that, RSTP can do better than the timers imply.

Bert

Thanks, make me more clearly.
From powerup, I still think that it should elect root bridge first.
The root election should same as stp. right?
st
.

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