# Trunk Configuration LAB

Video Activity

In this lesson we begin with a detailed topology diagram to demonstrate Trunk Configuration. We'll be using Switch 1 port 1, and at the other end of the same link Switch 2 port 1 of the topology diagram. You'll learn how to navigate go and launch Config Mode, where to define your configuration specs.

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Time
15 hours 34 minutes
Difficulty
Intermediate
CEU/CPE
16
Video Description

Trunk Configuration Lab In this lesson we begin with a detailed topology diagram to demonstrate Trunk Configuration. We'll be using Switch 1 port 1, and at the other end of the same link Switch 2 port 1 of the topology diagram. You'll learn how to navigate go and launch Config Mode, where to define your configuration specs. This lab also provides excellent syntax usage so you can see the importance of proper syntax nomenclature as well as correct switch use within the syntax.

Video Transcription
00:04
So now we move on to trunk ing configuration,
00:08
as you see in our diagram here in our apology on packet tracer
00:12
switch one
00:14
where I'm having my mouth right now.
00:17
Switch to
00:18
So it's three and switch for So the top left switch ISS. Which one? The top of right switches switched. Three.
00:28
The bottom left
00:30
between these four switches switched to and the bottom right is switched for. It's kind of hard to see. Switch one and two. Since the links are covering
00:39
the names,
00:41
I'm going to configure trunk ing
00:43
on switch one Port one
00:47
and switched to Port one.
00:50
If I have her in my mouse over these
00:52
and again, it's kind of hard to see because it gets too cluttered.
00:55
Uh,
00:56
switch one. Port one is connected to switch to port one
01:00
switch. One port to is connected to switch to port. To
01:06
switch. One. Port three is connected to switch. Three. Port three. This one's a little bit clearer as you see which 10 slash three is connected to switch to zeros. Last three. That would be fascinated and zero slash three
01:23
and switch one Port. Four. It's connected to switch three. Port four. So all four switches are connected to
01:33
another switch on port 1234
01:38
So,
01:38
just for these
01:41
and not to make it too complicated, I am going to configure trunk ing on switch one, port one and the other end of the link, which is switched to port one.
01:53
01:57
Maximize this
02:01
and we're inside of switch one.
02:05
And our switch has a name
02:07
because at the end of the day, I saved my configured. So when I restarted the lab, our work from yesterday is saved.
02:16
I say configure
02:19
terminal,
02:21
you go into config mode.
02:23
If you remember, this is where we do all our convicts from
02:29
next. I need to make changes to port one on switch one
02:34
because that's going to be a trunk.
02:35
Since it is connected to port one on switch to
02:39
so the rule and Cisco To make changes to a port, you have to first go inside of the port,
02:46
say interface
02:47
fast Internet zero slash one,
02:53
and you see that are prompt changed here to configure if
02:58
which means I am inside of interface Fascinating. At 01
03:06
now,
03:07
before
03:08
we manually configure trunk ing
03:12
and there is a way to manually set trunk ing,
03:15
I am going to
03:17
used dynamic Trucking Protocol
03:21
two. I don't negotiate trunk ing,
03:24
So if I do the command do show
03:29
interface
03:31
fast,
03:32
you turn it zero slash one,
03:39
followed by the keyword
03:43
which port?
03:46
You see that by
03:51
default? This port is in DTP dynamic auto mode.
03:58
So the switch we're using right now is a 35 60 switch. And if you remember, I said that all ports on switches that end with the number 60
04:08
have all the airports.
04:10
So switches
04:12
switches that have
04:14
the number 60 as their model number is the last number. And this is a 35 60 switch. Have all their pores by default in dynamic auto mode.
04:24
So this side on switch one port one isn't dynamic auto.
04:29
The other side switched to port one. It's a similar switch. It is also a 35 60. That port is also in dynamic auto. So by default, if two sides are
04:40
talk trying to talk to each other and both sides are dynamic auto, the trunk will not automatically go up.
04:46
So if I do the command do Show,
04:48
interface, trunk. You will see that I don't see anything
04:54
now if you remember from our lecture on dynamic trucking Protocol, If one side is dynamic desirable and the other side is dynamic auto, the port will become will be turned into a trunk.
05:08
So I'm going to say
05:09
switch port
05:12
mode.
05:15
And if I
05:15
execute the question mark or the help feature,
05:21
you see the word dynamic. One of the options is access, the other option is dynamic and the third option is trunk. When we created access ports, ports that only carry one villain, we used this access option. We said switch po'd mod access. Now I'm going to use the dynamic act option.
05:43
So I say switch port mode dynamic.
05:46
And now I have two options. Auto or desirable.
05:49
This port port F zero slash one on switch one is by default in dynamic auto mode, The other side on switch to Port one is also in dynamic auto mode. So I need to turn this into a dynamic, desirable
06:05
port to bring up the trunk.
06:12
So I execute the command Swissport mode dynamic, desirable and hit. Enter
06:16
and you see some logging messages appear immediately on the switch and it says line total call on interface. Fast interface Faceted at 01 changed to up
06:29
and then went back down. But then it went back up. It sometimes does that, uh, the poor bounces back and forth a few times before it steady steadies itself.
06:39
Now let's see if you have a trunk new show
06:43
into face
06:45
trunk
06:46
and here we go.
06:48
No
06:49
port f zero slash one Say's status. Trunk ing
06:57
the mood say's auto. Actually, this should say desirable. This is an error inside of packet tracer. So whoever programmed the simulator made an error and the mood still say's Otto, Although it should say desirable,
07:12
the encapsulation types A's
07:15
n hyphen it. 2.1 q.
07:18
The n stands for negotiated. So DTP was used between switch one Port one and switched to Port one to negotiate a trunk ing protocol. Remember, we have to trucking protocols. One is interest, which link, which is
07:34
Cisco proprietary and the other one, the open standard, is IEEE it 2.1 cube.
07:41
So switch one and switch to negotiated and picked it. 2.1 Q as their trunk ing protocol.
07:47
The N stands for negotiated.
07:50
The status is strong King and the native land by default is villain. One.
07:57
If you remember, the native villain off a 0.1 Q trunk is the villain that grows across the trunk.
08:05
Untaxed.
08:05
So this is the villain that the switch does not add a tag or an identifier to
08:13
the villains that are allowed on the trunk by default?
08:16
Well, this, which can have a total of 1000 and five villains. So by default, all villains are allowed over the trump. That could be a test question
08:26
Once again. By default, all villains are allowed on the trunk.
08:33
Now let's go look at switch to
08:35
and see if we have a trunk up on that side to which we should.
08:41
08:45
go. Do config mood by executing configure terminal
08:50
and say, Do show interface truck
08:56
again. We see
09:00
that fast Lieutenant 01 on switch to as mode by default set to auto, and this is correct.
09:07
Then calculation was negotiated to go to that one. Q. And the status is trunk ing
09:13
the native villain once again is villain one and all the lands are allowed on the trunk by default.
09:24
Gonna hop back to switch one.
09:26
You see the problem change to switch one from switch to.
09:31
Now. The next thing I'm going to do is I'm going to modify the villains allowed list.
09:39
You don't want to leave
09:41
all your villains open like this allowed over the trunk because it is a security risk.
09:46
So
09:48
I'm gonna execute the command, which poor
09:50
trunk
09:52
allowed
09:54
villain. And now I can create a list of allowed villains
10:01
for the trunk.
10:03
Now, by default be on Lee.
10:05
We only had veal and one on the switch to start off with. And then we created the land 1 50
10:13
So I'm gonna allow villain one
10:16
comma villain 1 50
10:18
And let's just say we had veal on 200 through
10:24
2 20
10:24
So I'm gonna allow villains 200 through to 20 also over the trunk.
10:31
I'm doing this. Just assure you that you have the option of allowing single bee lands with separated by a comma or a range of villains
10:41
separated by a hyphen.
10:43
So the villains allowed over the trunk.
10:46
Now we'll be villain one villain 1 52 100 to 2 20
10:54
Let's see if that list has changed when we look at our
10:56
trunk again. So I will execute the command. Do show interface trunk one more time, and you see that the villains allowed on the trunk list
11:05
has been modified to villain 11 52 100 to 2 20
11:13
Next, I'm going to change the native villain on the trunk to Villain 1 50
11:20
So I'm going to say switch port
11:26
trunk.
11:28
Native
11:30
villain 1 50
11:33
Since I've changed the native villain from 1 to 1 50 now well, at 1 50 will be the villain that goes over the trunk. Untapped. So which one will never add? Attack to villain 1 50
11:48
when it transfers. Is the trunk link as long as villain 1 50 is native?
11:52
Let's see if we actually this change took effect.
11:58
And if you see my native villain has changed from real and 1 52 villain
12:03
from villain one too real and 1 50
12:07
now, if we wait a little bit, we will see that the switch will start complaining that there is a native land mismatch, so I'm gonna leave switch. Here we go. I thought I would have to wait longer, but here we go.
12:20
So CDP is a protocol that runs between
12:24
Cisco Devices by default automatically. We haven't covered CDP yet, but this protocol seedy P is reporting that the native villain on the other end of the link, which is switched to Port One, is still real. And one in the native villain on this end of the link is villain 1 50
12:43
So to stop the switch from complaining every now and then,
12:46
we have to go to switch to restore what to switch to if you notice
12:52
and switch to is also complaining that the other end is Villain 1 50 I'm Bill and one as my native villain. So we're going to switch over. Need a villain to be land 1 50 on this end.
13:03
So first I go into the interface
13:09
fast. It's a net zero slash one,
13:11
and then I say same commands. Which poor trunk
13:16
allowed
13:18
villain
13:20
Well, screw sport Trunk Native
13:22
Vreeland.
13:24
1 50
13:26
Let's check to make sure
13:31
the villain has changed over. The native villain has switched over to 1 50 yes, it has
13:39
it is always a good idea to keep commands consistent on both ends off a trump's link.
13:46
So
13:46
on Switch one, we had modified the villains allowed on trunk list. Let's modify it on sweets to also.
13:56
So I'm going to say Switch Port
13:58
Strong
14:01
allowed villain 11 50
14:07
than 200 through to 20 to keep it consistent with the other end.
14:13
Now let's look at our trunk again.
14:16
New show interface trunk
14:18
and I'm shortening interface to I NT, which works just fine.
14:24
And our villains allowed on trunk list has been modified.
14:31
So let's pop back into Switch one.
14:35
And we are going to look at a little bit more detail for Port one on Switch one
14:41
new show
14:45
interface
14:48
Fast Ethernet
14:52
zero slash one
14:54
which port
14:58
and hear? Actually,
15:01
there is no mistake. Fassi Tenement Fascinating and zero slash one shows that is it. It is in dynamic, desirable mode. If we check on the other side, you will see that
15:11
switch to Port One is in dynamic auto mood, and I'm going to do that in just a minute.
15:18
You also see that the native villain for the 0.1 Q trunk has changed to villain 1 50
15:24
and the villains enabled, Or the trunk or the villains allowed over the trunk of the land. 111 52 100 through to 20.
15:35
Let's go check the other end,
15:37
Go to switch to
15:39
and I say, Do show I nt short for interface
15:46
fast Internet. I'm just going to use the letter f zero slash one
15:50
and S W for switchboard so I can shorten the command. This is the same command it actually says. Do show interface fast, Lieutenant. 01 switchboard
16:02
and I'm going to hit, Enter
16:03
and you see that switched to port run shows as dynamic auto.
16:10
The native villain of the trunk. Once again matches switch one, which is 1 50 the villains allowed over the trunk list also matches Switch one, which is 11 52 102 20.
16:25
Now we have seen
16:26
both
16:29
the dynamic Otto and the dynamic desirable mode between switch one and switch to
16:34
16:37
DPS last more than it can run in is mode on,
16:42
so I'm going to switch over to mode DTP mode on and unconditionally set switch one pork 1 to 2 trunk ing,
16:55
so I execute the command switchboard
16:59
mode
17:00
truck.
17:07
Now let's look at the trunk. Do show interface
17:12
new show
17:15
interface, trunk.
17:18
Now the mood stays on. This is DTP mode on
17:26
before it says it, said Dynamic should have said Dynamic, Desirable. It said Mode Auto, that was a mistake and packet tracer. But now it stays mode on.
17:37
17:38
and choose mode on on Switched to also. So I'm going to do the same command over Swissport mode
17:47
trunk.
17:49
Now
17:52
this command was rejected at this end
17:55
because the encapsulation type or the DTP mode on this end is set to auto, and the switch is basically telling me that if
18:03
if the mood is set to auto,
18:06
then you need to manually pick what type of trucking protocol you're going to use over this link. If you don't want to negotiate, you want to just unconditionally set this side to mode DTP mode on.
18:21
Then you better pick the trunk ing protocol. Also, either i sl or 0.1 cube.
18:26
So let's go ahead and pick 0.1 cube.
18:30
Switch forward
18:32
trunk
18:36
encapsulation,
18:37
and if I say space question mark and execute the help feature.
18:41
The only option we have is 0.1 Q.
18:45
Nowadays on switches, you don't even get the option of running. I sl
18:51
Why not?
18:52
Because I s l
18:53
carries with it
18:55
18:56
and I sl encapsulates the original frame in a 26 bite header
19:02
and a four bite footer that's 30 extra bites
19:04
0.1. Q. Simply insert a four bite tag into the original frame, so that's less overhead.
19:11
Now it is. Actually, this command won't even be available on the switch is because the switch will automatically picked that one. Q.
19:18
The reason this command exists in packet trace or still is because
19:23
this command is part off the CCN a course,
19:26
so pack it trace. They're supposed to be a learning to. Hence this command still exist in Packet Tracer.
19:33
So I'm going to say, Switch for trunk and cast relation
19:37
0.1 cube
19:38
and hit Enter. Now let's look at our trunk again.
19:44
So do show interface trunk. I'm simply scrolling through my command history, using the up and down arrow keys so I don't have to type them over again.
19:59
Actually, this should have changed over this end. Should have disappeared let me go ahead and manually said the encapsulation type on switch one. Also
20:07
for sport trunk encapsulation Got one. Q.
20:14
And now look at our trunk Do show interface trunk,
20:18
and you see that the encapsulation tight now
20:22
does not have it in front of it.
20:26
That is because now you're not negotiating the encapsulation, you are simply manually setting the encapsulation. 2.1 Q.
20:34
This should have changed over on switch to also. Now
20:38
let's bounce the port by shutting it down
20:44
and bringing it back up. So I simply executed the shut command and no shutdown Command to bring it back up.
20:52
And now let's look at our trunk.
20:56
The instilled has not disappeared on this end, and it really should so
21:03
switch port mode
21:06
strong.
21:07
That's manually set the trunk ing, too.
21:10
Just manually. Set the trunk into trunk, said the port to trunk
21:15
or DTP mode on.
21:17
And now, look, let's look at our trunk again,
21:21
Okay, that seemed to have worked.
21:22
The mod
21:23
for the trunk ing is on,
21:26
and the encapsulation is 0.1 Q. Without an end in front off it. That means you are not negotiating this trunk ing at this point any more.
21:37
21:41
Since we're not negotiating trunk ing,
21:44
we're not negotiating our trucking per call. I'm not asking the other end. Hey, what protocol between I sl and dot want to? Would you like to use? I have manually said it too
21:53
0.1 cue with the command
21:57
switchboard trunk encapsulation 0.1 Q. I have manually set the trunk ing encapsulation,
22:03
so I'm not negotiating that
22:07
I'm not negotiating whether I want to be a trunk or not.
22:11
I have simply set the mood to DTP on
22:15
or unconditionally set this support to trunk ing.
22:18
Do I really need DTP at this point,
22:22
or am I still running DTP? At this point?
22:26
Let's find out.
22:26
Do show Enter face
22:33
fast Internet zero slash one
22:37
foot sport.
22:45
And if I look,
22:48
my administrative trunk encapsulation is 0.1 cube,
22:52
my operational modus trunk.
22:55
22:59
However,
23:00
if I look at negotiation of trunk ing, it's still on, which means I'm still sending DTP frames back and forth between switch one port one and switch to port one.
23:11
That should not be the case because I'm using a bandwidth sending frames that I have no need for at this point.
23:18
So let's turn off DTP at this point
23:21
on. Switch to I'm going to do the command switch Port
23:26
No negotiate.
23:29
So I don't want to negotiate trunk ing with the other end at this point.
23:33
Also on switch one, I'm going to go execute the same command switch port.
23:38
No, negotiate.
23:42
Now let's check on both sides. So let's go to switch to first and see if I have turned off DTP.
23:52
And now if I look at negotiation of trunk ing, it stays off
23:56
because I don't need to send DTP frames across the link anyways, So I'm just wasting bandwith if I'm sending frames that I don't need. So I turned negotiation off
24:08
or I turned DTP
24:11
off.
24:12
Let's check on switch one. Also
24:15
gonna flip to switch one.
24:18
Do show interface Fascinating, as you know, slash one
24:25
switchboard
24:29
and also on this side. I see that negotiation of trunk ing is off.
24:33
Let's look at our show run or show running config.
24:40
Remember that is stored in ram and this is
24:45
our current configuration. The current changes that we have made, we haven't saved these yet, so let's look at them. Do show
24:53
running dash or hyphen Config
24:57
and scroll down to port one. And you see all the commands that we did our here.
25:04
Now, are these saved to our start up and sing?
25:08
Let's look at our startup Infect Do show
25:14
start
25:15
If I look at my startup config You don't see anything under port one
25:21
because we haven't saved These can fix yet,
25:23
so let's save them.
25:26
Remember, our safe command is copy
25:30
running config,
25:33
which is our source file too.
25:37
Startup config, which is our destination file.
25:41
I hit Enter
25:42
and it's asking me Are you sure you want to do this?
25:45
And I had enter again and it stays building configuration. Now let's look at our startup configure game.
25:52
Sure.
25:55
Startup config
25:56
on. We should see
26:00
all our config sitting here and we do
26:03
this concludes
26:07
the trunk ing configuration part of the lecture.
26:11
I am going to take a moment
26:15
since it will be redundant for you to sit here and watch me do all for these switches. But switch 123 and four. Port
26:22
123 and four. I'm going to execute the same commands that we just did on Switch one and switch to over and over again. Okay, folks, I have gone ahead and configured
26:34
Port 123 and four on each switch
26:38
into a trunk. So I just want to show you that they have been configured Show
26:44
interface
26:45
trunk.
26:47
And, as you see, Port one, too.
26:51
Three and four are all in mode on,
26:56
which is DTP mode on which is unconditionally set. Decide to trunk ing
27:00
and the trunk type. Is it? 2.1 cue status. Its trunk ing and the native villain has been changed for all ports to 1 50
27:07
That is switched one. Let's look at switch to
27:11
which two
27:14
maximize
27:15
show interface
27:19
shrunk
27:21
once again, you see port 123 and four are trunks. Let's check switch three.
27:32
Once again,
27:33
show inter
27:36
faces
27:37
trunk,
27:40
and we have four trunks on switch three. Moving on to switch for
27:47
And that said, Always check your work and verify that the changes you have made have applied before. Moving on to your next job
27:56
show interfaces
28:00
trunk
28:00
and once again on switch for we have poured 1 to 2 and four that are trunk ing
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