All right, let's log into the lab and make sure we can configure UDLD and loop
guard.
We're basically going to be doing the same configurations that we did during
the skill,
but this is our opportunity to log in, make sure we know how to configure it
and make
sure we know how to verify that it's working.
So task number one here says we're going to configure the link between switches
three
and four.
That would be gig one slash zero here.
I'm going to say config T interface gig one slash zero and we're told to
protect ourselves WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
protect ourselves
from unidirectional communication.
So I'd be UDLD and we have to assume the link is copper.
Now remember global configuration applies only to fiber ports interface level
configuration
applies regardless.
So if this is a copper port, I'm going to have to configure it on the interface
.
So we're in the right place interface gig one slash zero.
And then we're also told to ensure the link gets placed into air disable.
So I do UDLD port question mark.
And remember, I can hit enter here for normal, but if I wanted to go into air
disable, I
have to configure aggressive mode. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
have to configure aggressive mode.
So I'm going to configure that for aggressive.
And I do have to configure that on the other side, configure it on one side is
not going
to work.
So interface gig one slash zero on this side, UDLD port aggressive.
So now I should be able to run some of those UDLD commands such as show UDLD
neighbor.
And I can already see that I have my neighbor on the other side.
Now it's an unknown state here because I ran it so fast.
We should see that there we go.
We're in bi directional now we are receiving our own echoed keep alive messages WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
We're in bi directional now we are receiving our own echoed keep alive messages
.
Perfect.
So task number two is talking about switch five here.
Let's get over to switch five configure switch five to protect the network from
an
STP process failure.
We're going to do exactly the same thing here.
We want to make sure that the port that is currently in a blocking state so I
could do
show spanning tree blocked ports, find that that same interface is in a
blocking state.
And I want to make sure it stays in a blocking state if switch for stop sending
BP to use.
So simply put we want to configure a loop guard and we can just do that WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So simply put we want to configure a loop guard and we can just do that
globally or we
could do it on the interface.
Let's just do it globally spanning tree loop guard.
And then the command is default.
And so from here we should see that's protected.
Again, we can verify that show spanning tree interface tells us that
information gig three
slash one detail.
And we do see that it is enabled by default on the port.
Now I can go to switch for interface gig three slash one and say spanning tree WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Now I can go to switch for interface gig three slash one and say spanning tree
BP to
filter enable.
And then all we have to do is wait our 20 seconds.
And ideally we find that this does go into the STP inconsistent state with that
broken
status.
Otherwise, otherwise we'll form the loop because we just disabled BP or yeah,
BP to use getting
sent by switch four.
So we wait the max age timer here and there we go.
Loop guard has indeed blocked that port.
So these are two very critical configurations. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So these are two very critical configurations.
We mentioned this in the last video as well.
Our last skill BP to you guard route guard.
And now we're talking about loop guard and you do all four of these absolutely
belong
in our modern network configurations.
They belong in production.
We need to make sure we understand exactly how they work as well as where to
deploy them
in the network in order to protect our spanning tree topologies that we build
and then also
protect ourselves from loops that can indeed occur.
And it's a real threat.
It could actually occur in our environment if we don't have these WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
It could actually occur in our environment if we don't have these
configurations in place.
I hope this has been informative for you and I'd like to thank you for viewing.