In the previous video, we have created new topology for room 3. 2
Now in this video, we are going to connecting room 3 with room 1 and room 2. 3
Let’s just start. 4
Let’s connecting between switch room 2 to switch room 3. 5
Remember that interface between switch should be configured as trunk. 6
So here in the switch room 2, interface fa0/7 will become trunk, and in the switch room 3 7
interface fa0/5 will become trunk. 8
Let’s start with switch room 2. 9
Enable, configure terminal. 10
Interface fa0/7, switchport mode trunk. 11
Next let’s configure switch room 3. 12
Let’s go to interface fa0/5, and then switchport mode trunk. 13
Okay here we get an error “command rejected, an interface whose trunk encapsulation is 14
auto can not be configured to trunk mode” 15
So here we failed to configure this interface become trunk. 16
Before we talk about this, let’s talk about protocol in trunk, actually we have two protocol 17
in trunk, which is ISL and 802.1q. 18
ISL is cisco proprietary, this is means that ISL is only used if cisco switch meet with 19
cisco switch. 20
If cisco switch meet with others vendors, we can not use ISL. 21
But now ISL is no longer used. 22
I never see the implementation of ISL. 23
But 802.1q is open standard. 24
This is means that all vendors can use this protocol. 25
And this is the protocol that we will use in trunk. 26
In the switch 2960, it’s only support 802.1q. switch 2960 not support ISL. 27
So remember that switch 2960 is no longer support for ISL. 28
This is why when we type switchport mode trunk, there is no error, because the switch only 29
support 802.1q. 30
But when we configure switchport mode trunk in switch 3560, we got an error, this is because 31
switch 3560 is still support for ISL and 802.1q. 32
So before configuring mode trunk, we need to specify which protocol we want to use. 33
Absolutely we want to use 802.1q. because ISL is no longer used. 34
So here before switchport mode trunk, we need a command to specify the protocol we will use 35
the command is switchport trunk encapsulation dot1q. 36
And then here we can type switchport mode trunk. 37
Okay we have done. 38
Now let’s verify it. 39
Do show interface trunk. 40
Okay here we can see that now we have interface trunk, which is fa0/5. 41
Let’s also check in the switch room 2. 42
Do show interface trunk. 43
Okay here we have 2 interface trunk, which is fa0/5 that connected to switch room 1 and 44
fa0/7 that connected to switch room 3. 45
Now let’s ping between pc in the same vlan but different room. 46
Let’s start from pc vlan 10 in the room 3 to the pc vlan 10 in the room 2. 47
Here we can see that the result is success. 48
Now let’s try from pc vlan 10 room 3 to the pc vlan 10 room 1. 49
Okay here we can see that the result is also success. 50
Next let’s try for vlan 20. 51
From room 1 vlan 20 to the room 3 vlan 20. 52
Okay here the result is success. 53
From room 3 to the room2, here the result is also success. 54
Okay so now we have done configuring trunk in all switch. 55
So between pc in the same vlan but different room can communicate each others. 56
I think enough for this video. 57
Thankyou for watching and see you on the next video.