Alright, hopefully you had some fun configuring MST in the lab. If you had any
problems,
we're just going to go through all of the questions and make sure we have
solutions
for everything together here. So I'm going to start by configuring MST, so
spanning
tree mode MST on switch three, and I'll go ahead and configure those VLANs
because
that is what task one wants us to do. So we're going to go ahead and just do
that configuration
on all three switches, spanning tree mode MST, and then VLAN two through ten, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
on all three switches, spanning tree mode MST, and then VLAN two through ten,
spanning
tree mode MST, VLAN two through ten. I'd like to verify, so if I do a do show
spanning
tree here, we'll see that we are indeed running MSTP. And if I do that show
spanning tree
MST config, we should see that all of the VLANs are mapped to instance zero,
and that would
be the default configuration. So task two asks us to configure some of these
other parameters.
So we're going to into spanning tree MST configuration mode here, and we want
to configure a region
name of CBTN. We want to configure a revision ID of one, and then we want to WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
name of CBTN. We want to configure a revision ID of one, and then we want to
map VLANs one
through five to instance five. So instance five, VLANs one through five, and
then instance
ten, we want the rest of the VLANs, VLANs six through ten. So notice we don't
have to use
instances one and two, for example, we can just use whatever instance IDs make
sense
that helps us to remember which VLANs are in which which instance. So I can WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
that helps us to remember which VLANs are in which which instance. So I can
grab that
configuration and copy that to make sure that we get it everywhere. So spanning
tree MST
config pasted in to switch four, and spanning tree MST config on switch five,
and we'll paste
it in. So that should give us our configuration. Again, I can do a show
spanning tree MST config,
make sure that the VLANs, oh, we haven't exited. So that is a nuance, and you
may have noticed
that in the lab yourself, that until we exit out of the config mode, it doesn't WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
that in the lab yourself, that until we exit out of the config mode, it doesn't
actually
save. So let's go ahead and run that same command and confirm that now our
instances
are properly mapped. So we should be good to go there. Now task number three,
configure
switch three to be the root, and switch four to be the backup route for
specific VLANs. So if I go
to switch three, again, I can't do this on a per VLAN basis. So if I'm told to
make this the
root bridge for VLANs one through five, we're good, because that maps to an
instance. If I were told
to make it the root for VLANs three, four, and five, but not for one and two,
that would be impossible WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
that would be impossible
with MST. It's all or nothing. So I'm going to go ahead and do the spanning
tree MST five priority
command. And I'll just configure that for 4096. And then likewise, spanning
tree MST 10,
with a priority of 81 92. Now you could have chosen different values for that.
So whatever makes
sense from your perspective to make sure that we're the primary for MST five
and the backup for
MST 10 for switch three, switch four is the opposite of that. We're going to do
spanning tree MST of five WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
spanning tree MST of five
priority of 81 92 and spanning tree MST 10 priority of 4096. Now that does
actually combine
tasks three and four together, because three was asked to go to do one of those
instances task
forwards to do the other instance. So at this point, if I go to switch five, we
should see if I do a
show spanning tree root another great command that we use with rapid pvst plus
and pvst plus alone. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and pvst plus alone.
We see that MST five has a root port towards switch three and MST 10 has a root
port towards
switch four. So everything has configured appropriately here. The last couple
tasks just for fun.
Said go ahead and configure a hello timer for VLANs one through five. Well, as
we might recall,
we can't actually do just one through five, but we can accomplish the task by
still setting a global
hello time for MST to one. So that will set the hello timer to one second for V
LANs one through five, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
LANs one through five,
but it will also do it for all the other VLANs as well. Technically, that's
still a win. And we
want to go ahead and copy this and paste it onto the other switches in case
they become the root.
Switch four is the root for some of those VLANs, but keep in mind, whoops,
config T and then that.
But since we were only told to ensure that it's happening on on on MST five, it
really could just
go on switch three and then we're really accomplishing what we set out to do
until switch three goes
down and switch four takes over because remember timers only matter on the root WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
down and switch four takes over because remember timers only matter on the root
bridge for that
instance in this case. Last task switch five should be blocking on one of the
ports for all of the
VLANs. If we look back at our topology, we show that that would be blocking
this link here to
switch three for all of the all of the VLANs, all the instances. And we're told
to only configure
switch five for this task. Well, switch five is that would make it an inbound WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
switch five for this task. Well, switch five is that would make it an inbound
conversation.
We want to adjust cost. So I can just really raise the cost on gig two slash
one to make this
happen. And I'd want to do it on all instances. So let's just go back to switch
five interface.
Gig two slash one, and we'll just do a spanning tree. And we could do this on
just the instance
where it's not blocking, which should be MST five. But I'm just going to go
ahead and increase the
cost for all of the instances. And we'll just increase this looks like we're WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
cost for all of the instances. And we'll just increase this looks like we're
dealing with 20
K on all of these links. So I'll just increase it by 100,000. And that should
do the trick. So if I
do a show spanning tree blocked ports, we should now see that we're blocking to
slash one for all
of the instances. So this is a great opportunity for us to get comfortable with
MST again, MST is
is not starting from scratch. It's really all of the exact same concepts. We
just have to start
off by making sure our configurations are synced. It's those three parameters
or really three WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
or really three
configurations, because two of them are parameters. One of them is a mapping
system. But either way,
as long as those three things are synchronized, then we're good to go. And we
can use all of the
same configuration commands we've been doing, and just swapping out VLAN IDs
for instance IDs,
because that's how MST operates. I hope this has been informative for you. And
I'd like to
thank you for viewing.