Configuring a VLAN on a Cisco Switch

Objective: Segment the network by configuring VLANs to separate broadcast domains and improve security.

Prerequisites:

• A Cisco switch (e.g., Cisco Catalyst 2960)
• Administration console (telnet, SSH, or physical console)
• Administrator privileges

Steps:

1. Access the Cisco switch:
   • Connect to the switch via a terminal session (e.g., PuTTY).
   • Enter privileged mode by typing:
     bash

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     enable

2. Create a VLAN:
   • Enter global configuration mode:
     bash

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     configure terminal

   • Create a VLAN with a specific number (e.g., VLAN 10):
     bash

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     vlan 10
name Sales

3. Assign ports to the VLAN:
   • Select the interfaces to assign to the VLAN. For example, to assign interfaces 1 to 10 to VLAN 10:
     bash

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     interface range FastEthernet0/1 - 10
switchport mode access
switchport access vlan 10

4. Configure VLAN Trunking:
   • To allow a port to carry multiple VLANs (trunking), for example, for connections between switches or to a router:
     bash

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     interface FastEthernet0/24
switchport mode trunk
switchport trunk allowed vlan 10,20

5. Save the configuration:
   • Save the configuration to prevent losing changes after a reboot:
     bash

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     write memory

6. Verify the configuration:
   • Check that the VLAN has been correctly configured by typing:
     bash

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     show vlan brief