Time
15 hours 34 minutes
Difficulty
Intermediate
CEU/CPE
16

Video Description

Spanning Tree Enhancements This lesson focuses on two of the main enhancements made to the Spanning Tree Protocol since its original development in the 70's. You'll learn what Port Fast is and observe a quick diagram that demonstrates its functions. Then we cover BPDU Guard feature and how it works in conjunction with Port Fast.

Video Transcription

00:04
spanning three protocol has been modified slightly since. It's origen to enhance it. And these are called spanning tree enhancement for the ccn A. We're gonna cover two of these enhancements.
00:15
The 1st 1 is your port fast feature. For example, if you have a switch, which one and you have a bunch of PCs connected to it
00:24
PC one
00:27
PC to
00:29
and
00:30
PC three. I'm just gonna draw three
00:34
spanning tree when this switch powers on spanning three star sending BP to use.
00:39
And how long does it take spanning tree to convert who go from blocking to listening to learning to fording?
00:47
Well, it takes 20 seconds. It remains in blocking for 20 seconds,
00:52
then for listening and learning. It's 15 seconds each for a total of 50 seconds. So it takes 50 seconds for spanning tree
01:00
to converge and to put the ports
01:03
from blocking to forging.
01:07
Now, do these species understands founding three BB to use? No, they don't. So will these species need to wait 50 seconds for this switch to convert spanning tree before the species can talk to each other? Yeah, they would, unless you use the port fast feature
01:25
on these ports connected to
01:29
the end hosts. What the port fast feature does is immediately transitions the port from blocking to 14. It skips all the spanning three states, so the poor does not transition from blocking to listening to learning to fording.
01:45
And the port does not wait 50 seconds. It immediately jumps into fording
01:51
that is your pork past feature. The second feature is your B P. D. You guard with the beating you guard feature.
02:00
It is used in conjunction with the port Fast feature. Now what if somebody with malicious intent unplugged this PC from this port? Let's say this is Port three
02:14
and attach their own switch at the other end. Switch X. We don't know.
02:21
Then they can get all your traffic that's running between PC one and PC to if they have the correct villain information.
02:28
So how do we guard against this?
02:30
Well, if we enable the BP Dugard feature on Port three as soon as BP news are received because switch excellent, it powers up will start sending bpd use correct.
02:43
So as soon as a B p. D. U is received on Port 34 tree will be put in air disabled mode or in other words, will be shut down.
02:52
And that is what
02:53
the BP do you guard feature does. It's to prevent against malicious attack such a stiff.
03:00
Now, I'm gonna go ahead and show you the port fast feature and the BP Do you guard feature on
03:07
on the lab.

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Instructed By

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Junaid Memon
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