VLAN's

Creating a VLAN

  switch# config t
  switch(config)# vlan 5
  switch(config-vlan)# name engineering
  switch(config-vlan)# exit

Give ports access to VLAN

  switch# config t
  switch(config)# interface range FastEthernet0/20 - 24
  switch(config-if-range)# switchport access vlan 5

Configure VLAN Trunking between two switches

If you have two switches connected by a cross over, and there is a VLAN on each switch that you want to go over both switches, create the VLAN with the same name and number on both switches and the setup trunking as follows:

  switch# config t
  switch(config)# interface FastEthernet0/20
  switch(config-if)# switchport mode trunk
  switch(config-if)# switchport trunk allowed vlan 5

This enable trunking on the port, but then restricts it to just VLAN 5. You may also need to run this command:

  switch(config-if)# switchport trunk encapsulation dot1q