1
00:00:00,000 --> 00:00:07,000
So what happens when we set 1 side to manual trunking

2
00:00:07,000 --> 00:00:13,000
so int g0/0 switchport mode trunk

3
00:00:13,000 --> 00:00:17,000
notice we have to specify an encapsulation

4
00:00:17,000 --> 00:00:23,000
so switchport trunk encapsulation sot1q switchport mode trunk

5
00:00:23,000 --> 00:00:27,000
So I’ve manually configured switch 1 to use trunking

6
00:00:27,000 --> 00:00:32,000
so sh int g0/0 switchport

7
00:00:32,000 --> 00:00:35,000
so this side is configured as a trunk

8
00:00:35,000 --> 00:00:38,000
and is operating as a trunk using 802.1Q

9
00:00:38,000 --> 00:00:42,000
on this switch sh interface trunk

10
00:00:42,000 --> 00:00:47,000
notice it's negotiated to use trunking with 802.1Q

11
00:00:47,000 --> 00:00:52,000
so its currently trunking even though this side was configured for auto.

12
00:00:52,000 --> 00:00:55,000
So sh int g0/0 switchport

13
00:00:55,000 --> 00:01:02,000
This was configured to use DTP or dynamic auto mode

14
00:01:02,000 --> 00:01:08,000
but it became a trunk because the switch on the left was configured as a trunk.

15
00:01:08,000 --> 00:01:11,000
So if you configure 1 side manually

16
00:01:11,000 --> 00:01:17,000
the other side will automatically be configured as a trunk when DTP is used

17
00:01:17,000 --> 00:01:23,000
when this side is configured as an access port

18
00:01:23,000 --> 00:01:28,000
so sh int g0/0 switchport

19
00:01:28,000 --> 00:01:31,000
Notice it was statically configured as an access port

20
00:01:31,000 --> 00:01:33,000
and is operating as an access port.

21
00:01:33,000 --> 00:01:38,000
Negotiation of trunking is off on this side

22
00:01:38,000 --> 00:01:42,000
it’s dynamically configured to use auto

23
00:01:42,000 --> 00:01:46,000
but the operational mode has become static access.

24
00:01:46,000 --> 00:01:53,000
So if 1 side is configured as a trunk statically and the other side is configured

25
00:01:53,000 --> 00:01:58,000
to use  either dynamic auto or dynamic desirable a trunk will be formed

26
00:01:58,000 --> 00:02:03,000
but if 1 side is statically configured as an access port.

27
00:02:03,000 --> 00:02:07,000
The DTP side will become an access port.

28
00:02:07,000 --> 00:02:11,000
So the switch can dynamically be configured with the right mode.

29
00:02:11,000 --> 00:02:16,000
you can have a problem where 1 side is configured as access

30
00:02:16,000 --> 00:02:18,000
and 1 side is configured as a trunk port

31
00:02:18,000 --> 00:02:22,000
so you need to either manually configure both sides as a trunk

32
00:02:22,000 --> 00:02:28,000
or manually configure both sides as access or use DTP.

33
00:02:28,000 --> 00:02:35,000
The recommendation is that you manually configure both sides and turn off DTP

34
00:02:35,000 --> 00:02:42,000
So what we will do is do something like this on gigabit 0/0

35
00:02:42,000 --> 00:02:46,000
we’ve configured the encapsulation as dot1q, it’s an access port

36
00:02:46,000 --> 00:02:51,000
but to configure trunking, we type switchport mode trunk

37
00:02:51,000 --> 00:02:57,000
and we would type switchport nonegotiate to disable DTP.

38
00:02:57,000 --> 00:03:01,000
So this is the recommended configuration.

39
00:03:01,000 --> 00:03:04,000
Set your encapsulation to dot1q

40
00:03:04,000 --> 00:03:11,000
set the mode to trunking manually or statically and disable DTP

41
00:03:11,000 --> 00:03:14,000
Now we have to do that on both sides.

42
00:03:14,000 --> 00:03:19,000
So on this side, we will do something similar

43
00:03:19,000 --> 00:03:24,000
sh int g0/0 trunk

44
00:03:24,000 --> 00:03:29,000
notice gigabit 0/0 is configured as a trunk

45
00:03:29,000 --> 00:03:33,000
it’s configured manually or statically, so the mode is on.

46
00:03:33,000 --> 00:03:38,000
It’s currently trunking with the native VLAN set to 1.