In this video, we are going to start learning about vlan. So what is vlan? 2
And why we need a vlan? 3
We will learn with an example case. Here let’s say we have a room. And in this room we have 9 pc. 4
all of this pc is connected to a switch. 5
These 9 pc is separated to different division. These 3 pc is in accounting division, 6
these 3 pc is in the engineering division, and last, these 3 pc is in the marketing division. 7
Usually, each division will have different services. 8
Let’s say engineering division need higher bandwidth than others division. 9
Or let’s say marketing division is allowed to access social media like facebook, instagram, or others, 10
but others division is prohibited to access social media. 11
Because each division need different services like that, 12
so we will need to configure vlan for each division. Let’s say for accounting we use vlan 10, 13
engineering use vlan 20, and marketing use vlan 30. So each division will use different vlan. 14
And then, each vlan will use different network or different block subnet. 15
Let’s say vlan accounting or vlan 10, will use 192.168.10.0/24, for engineering or vlan 16
20 will use 192.168.20.0/24, and finally for marketing or vlan 30 will use 192.168.30.0/24. 17
If each division using different vlan and different network like this, 18
we can easily manage the service. 19
Here let’s complete the topology. So from the switch must be connected to a router, 20
and from router must be connected to internet like this. 21
Now let’s say we want to only allow access social media from marketing division, to do that we can 22
create a firewall or access list in the router to allow access to social media from 192.168.30.0/24, 23
and block access from the others. 24
Okay, so that is the first advantage of using vlan. 25
The second advantage that we can get if using vlan is separation of broadcast domain. 26
Let’s say here we have PC 1, and here we have PC 2. When PC 1 want to send packet to PC 2, 27
first PC1 will send ARP packet to the switch. This ARP packet is used to ask the mac address of PC 2. 28
After switch receive the ARP packet from PC 1, 29
switch will broadcast the ARP packet to all pc connected to it. 30
But because now we already have vlan, so the ARP packet from PC1 will not sent to other vlan, 31
but only sent to the computer that is in the same vlan with PC 1, which is PC 2 and PC 3. 32
The ARP packet will not sent to PC in the vlan 10 and vlan 20. 33
Okay, so this is the second advantage of using vlan, which is separation of broadcast domain. 34
Okay I think enough for this video, I hope you understand what is vlan 35
and why we need to configure a vlan. 36
Thankyou for watching and see you on the next video!