All right, it's time to jump into the lab and do some ether channel
configuration.
We're going to start with static ether channels.
Now the way this topology works in this lab environment, we've got a lab
diagram down
below, but just so we have it on the screen here, we are looking at two
switches, which
is one and two.
We have four connections between them.
We're probably going to want to ether channel those.
And we also have this access switch that has a pair of connections up to each
of the parent
switches.
So here we're on switch one, and let's go ahead and look at, now let's just do WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So here we're on switch one, and let's go ahead and look at, now let's just do
a show
spanning tree, and we'll look at VLAN one.
So looking at the spanning tree from a VLAN one perspective, we see that this
switch actually
has a lot of interfaces.
We're going to be focused up here on these three or four interfaces, gig zero
slash zero
through gig zero slash three, which exists between switches one and two.
So we see the effect of having multiple layer two links.
Every of them are in a blocked state here.
And that's just what we have to do from an ethernet perspective in order to WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And that's just what we have to do from an ethernet perspective in order to
make it
work loop free.
So the way we prevent that and is, well, I guess bundle all of this bandwidth
together
as well is to use an ether channel.
So we're going to do a config T, we're going to get onto that range of
interfaces gig zero
slash zero through three.
And we're going to use the channel group command.
Now this channel group command is going to allow us to create that virtual port
channel
interface.
So when I do channel group and question mark, I see that I can number this. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So when I do channel group and question mark, I see that I can number this.
And so if I make, for example, channel group 10, this will make the interface
port channel
10 on the switch here.
And then I'm going to say mode.
And then the question mark here shows me those five different options we talked
about where
we've got auto and desirable, which are, which is for PAGP, PAGP, there we go.
And we also have active and passive for LECP.
And then mode on is simply saying, Hey, we want to force these ports into an WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And then mode on is simply saying, Hey, we want to force these ports into an
ether channel.
So we're going to say mode on here.
And then I can do a show run interface port channel 10.
And we see that there's no configuration on it.
So I can get on to interface port channel 10 and say, let's place this into
switch trunk
encapsulation dot one queue and switch mode trunk.
So we're converting it to a trunk.
So I just place that onto interface port channel 10.
If I do a show run on interface, just pick gig zero zero, one of these member WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
If I do a show run on interface, just pick gig zero zero, one of these member
interfaces,
we see that the configuration that I put on the parent interface, this port
channel interface
got pushed down to the member interface.
So this is the relationship that we want to work with.
Any configuration we want to add should go on the port channel interface so it
can push
down to all the member interfaces.
So from here, we can do a verification command to see what it's looking like.
And we're going to find that way.
Well, at this point, it's not really working, or at least it shouldn't be, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Well, at this point, it's not really working, or at least it shouldn't be,
because I've
put the port channel on this side, but not the other side.
And this is what I'm talking about here.
We do see that we're getting all kinds of errors, because we're fortunately
able to interpret
some STP BPDUs and figure out that maybe the other side doesn't agree with us
on the
whole port channel thing.
So if I do a show ether channel summary, this is a really good command that we
're going
to want to get used to, and it shows that port channel 10, if we look at SD in WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
to want to get used to, and it shows that port channel 10, if we look at SD in
here,
the S is going to stand for switching.
It basically means that we're in a layer two operation rather than layer three,
and then
the D is going to also tell us something important, which is that we are in a
down state.
Remember what we said before, we want to see these capital P's.
It tells us we're in a port channel.
So the fact that we're in, you know, the S is just telling us layer two, the
fact that
we're in a down state, all these member interfaces are in a down state, that's
because really
the switch is leveraging spanning tree to say the other side isn't configured WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
the switch is leveraging spanning tree to say the other side isn't configured
yet.
So let's get on to switch to we'll do a show CDP neighbor just to make sure
that we know
which ports we're using.
Switch one is connected.
It looks like gig zero zero to gig zero zero, gig zero one to gig zero one and
so on and
so forth.
So I'm just getting on to those interfaces, interface range, gig zero slash
zero through
three.
And this time I'm going to do something a little different.
I'm going to say switch trunk encapsulation dot one Q and switch mode trunk. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
I'm going to say switch trunk encapsulation dot one Q and switch mode trunk.
So I just place these member interfaces into a trunk.
Now I can use that channel group 10.
In fact, let's just a 20 mode on remember, we use 10 on the other side 20 on
this side.
And what we're going to find is that ID doesn't matter.
It's only locally significant.
So in the real world, we try to line them up, but it's important to recognize
sometimes
that this is just an identifier.
It doesn't actually get used at the control plane or the data plane.
It's just something that we can look at and say, Hey, that is port channel 10 WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
It's just something that we can look at and say, Hey, that is port channel 10
between
those two switches.
So port channel 20, if I do a show run interface on port channel 20, we're
going to find that
it already comes equipped with a couple commands because these commands were
the same on those
member interfaces.
It was able to interpret that it should place the port channel into that.
Now if there's any issues whatsoever, I would just recommend getting on to this
interface
range and doing a default interface or getting rid of the commands that might
be preventing
it from getting added to a bundle. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
it from getting added to a bundle.
Because for example, if I were to let's just let's see here.
So do show IP and brief.
We see we've got a couple more interfaces here.
So if I were to do a show run on interface gig one zero, it's not in trunk.
So if I get on to gig one zero and say, Hey, I want you to be part of this
channel group
channel group 20 mode on.
So the IO will keep.
So remember, we said that iOS XC has a limit of eight ports in the virtual WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So remember, we said that iOS XC has a limit of eight ports in the virtual
space.
These virtual switches, they do limit us to four.
So that's something to keep in mind as well.
So different platforms, especially the virtual platforms might be a little
different.
So if I were to get on to and let's just say gig zero three and say no channel
group 20
mode on.
Now if I do a show either channel summary, we should see that we only have
three ports
in the channel and we do now I can go into gig zero one and say channel group WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
in the channel and we do now I can go into gig zero one and say channel group
20 mode
on.
All right, so now if I do a show run on interface gig one zero, notice exactly
what this error
message actually told me.
It's that this doesn't match the configuration.
So we might in some situations see that, you know, like in this example, I don
't have this
in a trunk operation, port channels already in a trunk operation, and therefore WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
in a trunk operation, port channels already in a trunk operation, and therefore
they're
not compatible.
Other times it might take those ports and push configuration down, especially
if it's
from the perspective of adding configuration to the port channel interface.
So sometimes iOS will handle it for us.
Other times we're going to have to handle it ourselves.
So if I do a show ether channel summary, we're going to find that one of these
ports is in
a suspended state because it is not compatible with the port channel. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
a suspended state because it is not compatible with the port channel.
As soon as I say, hey, let's go ahead and put you into a trunk, then it will
show up.
But I do want to just say default interface gig one zero, which will pull it
out of being
in the bundle, and let's get back onto gig zero three and say channel group 20
mode on.
There we go.
So show ether channel summary.
I want to make sure that all four are online.
They all have that capital P there over on the right. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
They all have that capital P there over on the right.
Each port is in the port channeled state.
The U here replaced the D. So we see over here it's up and down, or I guess
they technically
say in use.
But you know, however you want to think of it, I always think of it as being up
.
But then over here, we see that we get different statuses as well, like P, like
we said, being
part of the port channel, a lowercase s is for being suspended.
And we have now seen those specific examples throughout this video.