Tuesday 30 October 2018

Virtual Local Area Network (VLAN)

VLAN is a logical grouping of network users and resources connected to administratively defined ports on a switch. VLANs are given the ability to create smaller broadcast domains within layer 2 switched internetworks by assigning different service switches to different subnetworks. A VLAN is treated like its own subnet or broadcast domain, meaning that frames broadcast into the network are only switched between the ports logically grouped within the same VLAN. By default, hosts in a specific VLAN can’t communicate with hosts that are members of another VLAN, so if you want communication, we need a router or Inter-VLAN Routing (IVR).

Here is some basic information about VLAN:

· Divides a single broadcast domain into multiple broadcast domains
· VLAN provides layer 2 security
· VLAN 1 is the default VLAN
· We can create VLAN from 2-1001
· Can be configured on manageable switches only

Configuring basic VLAN on switch:

Topology

GOAL:

create four VLANs (10,20,30, and 40).
configuring port f 0/1 in to VLAN 10
configure multiple ports (2,3, and 4) to VLAN 20

Switch(config)#vlan 10
Switch(config-vlan)#name sales
Switch(config)#vlan 20
Switch(config-vlan)#name marketing
Switch(config)#vlan 30
Switch(config)#vlan 40

Switch#show vlan

VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4
Fa0/5, Fa0/6, Fa0/7, 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
Gig0/1, Gig0/2
10 sales active
20 marketing active
30 VLAN0030 active
40 VLAN0040 active
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
10 enet 100010 1500 - - - - - 0 0
20 enet 100020 1500 - - - - - 0 0
30 enet 100030 1500 - - - - - 0 0
40 enet 100040 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 0 0
1003 tr 101003 1500 - - - - - 0 0
1004 fdnet 101004 1500 - - - ieee - 0 0
1005 trnet 101005 1500 - - - ibm - 0 0

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------

Remote SPAN VLANs
------------------------------------------------------------------------------

Primary Secondary Type Ports
------- --------- ----------------- ------------------------------------------

To shift the ports

Switch(config)#interface fastEthernet 0/1
Switch(config-if)#switchport mode access
Switch(config-if)#switchport access vlan 10

Switch(config-if)#exit

Switch(config)#interface range fastEthernet 0/2- 4
Switch(config-if-range)#switchport mode access
Switch(config-if-range)#switchport access vlan 20

Switch(config-if-range)#exit

Switch#show vlan

VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/5, Fa0/6, Fa0/7, 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
Gig0/1, Gig0/2
10 sales active Fa0/1
20 marketing active Fa0/2, Fa0/3, Fa0/4
30 VLAN0030 active
40 VLAN0040 active
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
10 enet 100010 1500 - - - - - 0 0
20 enet 100020 1500 - - - - - 0 0
30 enet 100030 1500 - - - - - 0 0
40 enet 100040 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 0 0
1003 tr 101003 1500 - - - - - 0 0
1004 fdnet 101004 1500 - - - ieee - 0 0
1005 trnet 101005 1500 - - - ibm - 0 0

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------

Remote SPAN VLANs
------------------------------------------------------------------------------

Primary Secondary Type Ports

------- --------- ----------------- ------------------------------------------