What you'll notice the spending tree convergence is very quick and that's because we're running rapid
previous t plus I didn't make any changes on the switches from a spending tree point of view.
So the command show run piping CLEET span shows the default config and notice the spending tree use
these rapid PV T in the output it shows as always T-P or Reppert rapid spending tree.
But this is actually Rapide per villaine spending tree.
We can change the mode of spending tree.
But before I do that just to make the point again at the moment Sze spending tree on switch three shows
that to the root port is gigabit is 0 1 the support.
If I shut that port down
and then top shows spending tree again what youll notice is gigabit to 0 0 is the root port.
Convergence is very quick with rapid spending tree because it doesnt use timers.
So the max age and for delay time is not to be used for convergence.
The switches send messages to each other with rapid spending tree to enable quick convergence.
So now if we change the spending tree type mode to Peavey's t we should see that spending tree takes
a lot longer to converge.
So I'll change that on the old switches.
So which three switch for
switch five
subaccount switch three show spanning tree.
Notice we can see that the switch is still learning which ports are the root port designate a port or
blocking port when in the learning state.
Traffic will be blocked user traffic will only be forwarded when ports transition to a forwarding state.
At the moment you can see that the spending tree protocol used or shown here is trouble.
But once again you need to be careful because on Cisco switches even though it displays on trouble we
are actually using previous t Peavey's t is once again backward compatible so it will be able to talk
to an ADA.
Toward D switch from another vendor as an example so we can see I triple E in the output here.
So once again shows spanning tree the root port.
In this case is now gigabit.
0 0.
So what happened because previously we had to switch one as the root.
It still has a command
show spending tree shows us that the switch is the root of the topology but get 0 or 1 is not shown
in the output.
Because I need to know shut to that port so can t interface gigabit to 0 or 1.
No Schutt shows spending tree noticed that port is a listening port gig but 00 is a blocking port so
this port is blocking this port is listening
and what you'll notice is it'll take it a while to converge or put an IP address on the switch.
We'll be waiting.
And then I'll demonstrate this again
put my address on which one
will know shut the interface so paying ten on one one to one can paying itself switch three.
No shut the interface.
Paying 10 to 1 to 1 to 1 pink succeed so I'll just do that again.
Notice the ping from switch three to switch one succeeds.
Show spanning tree convergence has taken place because gigabit 0 1 is the root port and is forwarding.
But now if I shutdown gigabit 0 1 and then try paying switch 1 The port has gone down but pings are
failing even though we have a redundant link show spanning tree shows me that of Route port is still
learning still learning pings fail previous t takes a long time to converge.
Can take 30 seconds for that convergence to take place.
As you can see there it's just happened show spending trees shows us now that kickabout 0 1 is forwarding
But once again if I know Shutt gigabit 0 1 and did the ping again the ping would fail because it now
needs to learn that this is the better path.
So spending tree.
Notice the root port.
Gigabit 0 1 is in the listening state so we have listening.
Then we have a learning and after a while it should go to forwarding.
But that can take 30 seconds.
So it's still learning.
Now it's gone to forwarding and now Ping's will succeed.
So ports have different states in a blocking state.
Use a traffic is not forwarded.
The switch doesn't.
MAC addresses based on frame's received.
This is a stable state for a port a listening and learning port.
Do not forge frames either listing ports don't learn MAC addresses based on frames received.
In other words they don't update the MAC address table.
A learning port does update the MAC address table.
This is a temporary state with transitionary state while the switches to learn the topology in affording
state frames are forwarded.
MAC addresses a Lent and this is a stable state.
In other words this is not a transition restate the state will stay that way until there's a change
in the topology.
A disabled port doesn't receive frames doesn't Ford frames doesn't learn about MAC addresses on a port
and this port will stay in that state until you enable the port.
Now if we change that to rapid spending tree so spending tree mode rapid Peavey's t what we should notice
is that convergence takes place a lot quicker.
I'll only enable rapid spending tree on switch 1 2 and 3 show spending tree roll to show spanning tree
shows us that the spanning tree mode now enables these rapid PV lines spending tree.
We've got a pod cast using gigabit 0 1 so as you can see gigabit 0 1 is the root port.
The switch can ping switch one I'll shut that port down.
And when we do a ping again it instantly can ping.
So which one.
Even though we've just seen the interface go down in the output here because spanning tree converge
is a lot quicker when using a rapid spanning tree.
So the moral of the story is that in the real world you want to use a rapid previous t rather than previously.