VLAN:
1. VLAN – VIRTUAL AREA NETWORK
2. VLAN is any broadcast domain that is partitioned and isolated in a computer network at the data link layer.
3. VLAN works by applying tags to network frames and processing those tags in network systems.
4.Create the appearance and functionality of network traffic that is physically located on a single network but acts as if it is split between separate networks
5. In this way, Vlan can keep the network application separate even though it is connected to the same physical network and without the need to deploy multiple cabling sets and network devices.
EXAMPLE:
In the figure above, there is a router connected to three switches, and each switch has many systems connected to many systems. So all End devices are connected to the same Local Area Network. So on this Network, the End device of any switch can access data from every end device in the network.
Let’s assume a scenario, you are a network administrator at a company called XYZ, you have three departments in your office
1.VLAN _ Admin- 3PC
2.VLAN _ Pro -3PC
3.Vlan _ Dev -6PC
So you are given a job to restrict communication between the three departments, i.e. the PC in the executive department can only communicate with systems in the same department. It should not access resources in the Pro or development department and in every department the same. what is the solution to this problem ??? reply VLAN
We can create three VLANs for each department and restrict access. This can be configured on every switch within the CLI
VLAN 100 – Admin-FE 0 / 2.0 / 3.0 / 4 (Interface used to connect the switch)
VLAN 200 – Pro-FE 0 / 2.0 / 3.0 / 4
VLAN 300 – Dev-FE 0 / 2.0 / 3.0 / 4.0 / 5.0 / 6.0 / 7
By doing this, we split the Network into three sub-parts without using routers or switches etc.
CODE:
Switch> en # Enable configuration
# Change configuration
Enter configuration commands, one per line. Finish with CNTL / Z.
Switch (config) #vlan 100 # create a VLAN and report any given number as 100
Switch (config-vlan) #name admin # report a name as an administrator
Switch (config-vlan) #exit # Exit VLAN config
Switch (config) #interface fastethernet 0/2 # interface will be added to VLAN 100
Switch (config-if) #switchport mode access # change switchport mode for access
Switch (config-if) #switchport access vlan 100 # command to access vlan 100
Switch (config-if) #exit
Switch (config) #exit
—————————————— For FE 0/3
Switch (config) #interface fastethernet 0/3
Switch (config-if) #switchport mode access
Switch (config-if) #switchport access vlan 100
Switch (config-if) #exit
Switch (config) #exit
—————————————- For FE 0/4
Switch (config) #interface fastethernet 0/4
Switch (config-if) #switchport mode access
Switch (config-if) #switchport access vlan 100
Switch (config-if) #exit
Switch (config) #exit
—————————————- to see the VLAN you have created
Change#
% SYS-5-CONFIG_I: configured from console to console
show vlan # command
OUTPUT:
VLAN Name Status Ports
—- ——————————– ——— —– ————————–
1 default active Fa0 / 1, Fa0 / 8, Fa0 / 9, Fa0 / 10
Fa0 / 11, Fa0 / 12, Fa0 / 13, Fa0 / 14
Fa0 / 15, Fa0 / 16, Fa0 / 17, Fa0 / 18
Fa0 / 19, Fa0 / 20, Fa0 / 21, Fa0 / 22
Fa0 / 23, Fa0 / 24, Job0 / 1, Job0 / 2
100 admin active Fa0 / 2, Fa0 / 3, Fa0 / 4-> VLAN WE CREATED
SUB CLOTHING
1. A subnet or subnet is a logical subsection of an IP network. The practice of splitting a network into two or more networks is called subnetting.
2. Computers belonging to a subnet are addressed with the same most significant set of bits in their IP addresses. This results in an IP address being logically divided into two fields: the network number or routing prefix and the remaining domain or host identifier. The resting area is an identifier for a particular host or network interface.
3. When the routing prefixes of the source address and the destination address are different, traffic is exchanged between subnets via routers. The router acts as a logical or physical boundary between subnets.
4. The benefits of connecting an existing network to a subnet vary with each deployment scenario. It is necessary to allocate address space efficiently in the address allocation architecture of the Internet using CIDR and in large organizations.
SUBNETING USES
TO REDUCE COST
– TO REDUCE IP WASTE
COMPANY – SALES, HR, DEVELOPERS, SUPPORT – 100, 200, 300, 400
HOME – DESKTOP, LAPTOP – 2 COMPUTERS.
CLASS C = 254-2 = 252 HOSTS WASTE.
THIS CAN BE AVOIDED BY SUB-CLOTHING.
ÖR: 255.255.255.0 – 11111111.11111111.11111111.00000000 – 2 COMPUTERS
111111 – CONVERTING TO N / W
11111111.11111111.11111111.11111100
255.255.255.248 – SPECIAL SUBNET MASK
HOW SUB-GRINDING WORKS
CALCULATION PROCESS OF WASTE HOST BITS AND
CONVERTING THE WASTE MAIN FINISH INTO NETWORK BITS.
SCENARIO 1
SALES – 120
HR – 120
STAGE 1 : TO FIND CLASS
NUMBER OF COMPUTERS = 120 + 120 = 240 <254
WE CAN USE CLASS C
STEP 2: TO FIND THE ‘N’
‘N’ – number of bits to borrow
2 power n> = Number of Required Networks
2 power n> = 2
n = 0
2 power 0 = 1> = 2 wrong
n = 1
2 forces 1 = 2> = 2 true
n = 1 (number of bits to borrow)
STEP 3: TO FIND CSM
CLASS C
DSM – 255.255.255.0 – 11111111.11111111.11111111.00000000
CSM – 11111111.11111111.11111111.10000000 – 255.255.255.128
STEP 4: CALCULATION OF N / W AND HOST NUMBER
NO OF N / W = 2 power n
NUMBER OF HOST = 2 power h and -2
N / w number = 2 power 1 = 2 mesh
Number of Hosts = 2 power 7 and -2 = 128-2 = 126 hosts.
STEP 5: IP ASSIGNMENT
A + B = C + 2 = D – 1 = E
SALES
192.168.1.0 ————– 192.168.1.127
0 – A
126 – B
0 + 126 = 126 + 2 = 128 – 1 = 127
HR
192.168.1.128 —————- 192.168.1.255
128 – one
126 – B
128 + 126 = 254 + 2 = 256-1 + 255
————————————————– ————————————————– ——-
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