Now to improve spanning tree performance we want to make these ports.
Point to Point spanning tree ports.
Point to Point Spanish three ports converge a lot quicker when using rapid spanning tree.
At the moment on our switches such as Switch three we can see that the ports are shared ports they're
going to take a lot longer to converge so interface of range gigabit 0 0 to 1 spanning tree link type
point two point.
This will allow spanning tree to converge a lot quicker.
Notice the ports on our point to point links.
That's typically determined by the speed and duplex.
At the moment these switches in the lab are set to alter negotiate speed and duplex.
You might want to hard code some of those options.
If a port is set to full duplex it will become a point to point port in spanning tree.
As you can see here for VLAN 10 gigabit 0 0 and 0 1 point to point links but gigabit 0 2 is a shared
link show interface gigabit 0 2 shows me that we are using or 2 duplex or 2 speed negotiation in a physical
network.
We may want to hard code speed and duplex or when it negotiates to use full duplex the porch will become
a point to point link between genius 3.
It's not negotiating that so I want to manually set the port type two point two point in spanning tree.
So let's do the same on all the switches so switch for shows spanning tree VLAN 20 as an example can
see the ports a shared interface range gigabit 0 0 to 1 on the uplinks spanning tree link type point
two point shows spanning tree v land 20.
Notice those ports in our point to point.
Let's do it on the core switches as well.
So at the moment shows spanning tree v land 1 all my ports have a type of shed including the link aggregation
so interface range gigabit 00 to 3 spanning tree link type point to point shows spanning tree v land
one as an example.
Ports are still showing as shared on some of the ports gigabit 1 0 is the link to the host.
That's a K port.
Channel is showing up a shared cell going to the port channel
and lets configure that as a span entry point to point link show spanning tree v land 1 all ports are
now point to point on the core.
So these links all point to point.
We'll do the same on switch to so interface range gigabit.
0 0 2 3 spanning tree link type.
Point to Point interface port.
Channel 1.
Make it point to point shows spanning tree v land 1 or ports are point to point this port is still shared
so I could make that a point to point link.
But for the moment I'm going to leave that as it is because we can enable port Fost on these links to
increase the throughput of spending through convergence on those ports shows spanning tree v land and
10 billion.
Now let's test some of the convergence.
I'm going to send a continuous ping from P.S. 1 so row 1 pretending to be our P.S. to the course switch
and let's see how good the convergence is so on write a 1
ping tendered 1 to 10 at 1 ping succeeds but I can repeat to the ping let's say ten thousand times before
a presenter on switch three so the switch here
shows spanning tree big land 10.
We can see that the root port is gigabit 0 0.
This port is an alternate port so we'll stop the ping constantly interface gigabit 00 shut it.
Notice we've lost a ping.
We're losing a few pings here.
So the convergence is taking a while one of the things we can do to speed up convergence
is change.
This port.
Notice the state is learning gigabit.
0 1 has gone forwarding already.
But notice this port is still learning because it's a shared port it's going to take longer to converge.
So took a while for that port to converge.
Could take like 30 seconds for it to converge.
So point to point lengths converge very quickly as an example when I shutter this port down this port
very quickly went to the forwarding state.
If I'm no shut that port again shows spanning tree Vila and 10 you can see that port is already forwarding
so very quickly this port went to forwarding and this port went to blocking.
But the problem is the port to the host is blocking because this is a shared port so shared ports go
through the normal spanning three times of blocking listening learning forwarding so it's going to take
it a while for the port to start forwarding notice.
We're learning now and then after a period of time it starts forwarding.
So if you don't have a switch connected to this port you can improve the convergence of that port by
making it a spending tree port Fost port so I can specify port first here.
Notice we warned that this should only be enabled on ports where we don't have switches connected so
we shouldn't have hubs or switches or other devices that can cause loops in the network on these ports.
So our pings are continuing shows spanning TV Land 10:00 shows me that the port of the shared port.
But now when I go into gigabit 0 0 and shut the port down port is gone down no notice gigabit 0 1 is
already forwarding
it's taking a while because I put it looks like I put the command on the wrong port.
So let's have a look again at the config
I incorrectly configured port Fost on gigabit 00.
So let's fix that problem.
Interface gigabit 00 no spanning tree port Fost edge to show run interface gigabit 00 no shut the port
now and then let's go on to gigabit 0 to a top spanning tree port Fost and see if I did this right now.
So do show interface gigabit 0 to this port is now a port first port or what's called an airport which
is correct to show run gigabit 00.
That shouldn't be a port for support and it's not and neither should gigabit 0 1.
So that looks better to show spanning tree v land 10.
Notice the difference.
This is now a shared edge port that looks a lot better.
Let's do the ping again at the moment gigabit 00 is the route port so interface gigabit 00.
Shut the port down.
Let's see if we lose as many pings and as you've noticed they we only lost a single ping so I'll break
that ping.
We lost one ping we lost this lost one when I broke the ping but we only lost a single ping when the
interface went down.
So that's a lot better than we had previously.
So do show spanning tree V Line 10.
Notice gigabit 1 slash 0 is the route port.
I'll send 100 pings now and let's no shut the interface.
Make that a thousand shows banning tree VLAN 10.
What you'll notice once again is it dropped a single ping over there and it immediately reverted to
port one being the route port.
So what's the moral of the story.
These links need to be point to point links.
This link needs to be a port first port.
In other words a large port.
Compare that to switch for on switch for this as a shared port so it's going to take a lot longer for
this to converge
on this switch.
We want to go in gigabit 0 2 and Type spending 3 port fast
and now when we type show spending TV Land 20 notice it's a shared edge port and we could do something
similar now en route to aisle paying ten to one to 20 to 1 and repeat that thousand times again gone
to gigabit 00 start the ping and I'll shutter the port down notice we lost one ping.
So do shows spanning tree v land 20 in this example forwarding port is now this port.
It's the route port this port is the edge port to the ping again on those shut gigabit 00 now gigabit
00 is the route port and it's already forwarding
the convergence is a lot better than we had previously we didn't even lose a ping in this example.
So let's do that process again to a ping.
Shut the port down you've lost a ping but only one all no shut to the port
just to quick I'll shut it down again to ping again port is shut no shut it shows spending tree V Line
to show spending tree v lan 10 or 20 in this example gigabit 00 is the route port gigabit 0 is the alternate
port gigabit 0 2 is a shared edge port so once again to optimize spanning tree make all ports point
to point links between you such as make your ports to your edge devices spanning tree port Fost or edge
ports as it's called in the industry so Cisco term is Port fast.
Other vendors will call these edge ports and we could do the same on these two ports here.
So the last thing we need to do is on such one go on two gigabit one slash 0 and type spending tree
port fust and then do the same on switch to interface gigabit Wan slash zero spending tree port Fost
show spanning tree v land one gigabit one slash zero is an edge port on such two shows spanning tree
villain one on such one notice this is an HD port here so we've optimized spanning tree by making all
of these ports.
Point to Point links in spanning tree these ports are edge ports and these two ports are bonded in a
link aggregation or ether channel.
So once again on switch one show spanning tree v land one.
Notice this is a port channel and it's a point to point to link spanning tree has been optimized.
Now that we've optimized layer 2 We need to look at layer 3 functionality and specifically the default
gateways of devices in the topology.
We also need to think about routing how are we going to root from these devices onto the Internet.
So we'll cover that in subsequent videos.