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VLAN & Switching

VLANs (Virtual LANs) are a way to logically segment a network into multiple broadcast domains.

VLAN Tagging, Trunk, and Access Ports​

  • VLAN Tagging (IEEE 802.1Q): A method of inserting a VLAN tag into an Ethernet frame to identify the VLAN to which the frame belongs.
  • Trunk Port: A trunk port is a port on a switch that is configured to carry traffic for multiple VLANs. Trunk ports use VLAN tagging to differentiate between the traffic from different VLANs.
  • Access Port: An access port is a port on a switch that is assigned to a single VLAN. Traffic on an access port is untagged.

nmcli connection add type vlan examples​

You can use the nmcli command to create and manage VLAN interfaces in Linux.

  1. Create a VLAN interface: This command creates a new VLAN interface named vlan10 on the eth0 physical interface with a VLAN ID of 10.

    sudo nmcli con add type vlan con-name vlan10 ifname vlan10 id 10 dev eth0

  2. Assign an IP address to the VLAN interface:

    sudo nmcli con mod vlan10 ipv4.addresses 192.168.10.10/24
    sudo nmcli con mod vlan10 ipv4.method manual

  3. Bring up the VLAN interface:

    sudo nmcli con up vlan10

  4. View the VLAN interface:

    ip addr show vlan10