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Terme informatique

VLAN

A virtual local network that logically separates several groups of, equipment on the same physical infrastructure.

Networking
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Simple definition….

One VLAN allows you to create several independent networks with the same Switches, for example one network for employees and another for guests.

Technical definition….

The frames can be identified by an IEEE 802.1Q tag. Access ports usually carry a single unmarked VLAN, while the trunks carry several VLAN. Communication between VLAN requires routing.

What’s the point?… ?

To divide usage, enhance safety and limit areas of dissemination.

Concrete example…

The posts are placed in VLAN 10, the servers in VLAN 20 and the guests in VLAN 40 without buying three separate physical networks.

Common problems….

  • VLAN absent from the trunk
  • Port configured in wrong VLAN.
  • Incoherent native VLAN
  • Inter-VLAN rules too permissive or blocking

Switch. · Router. · LAN · Firewall · DHCP

To be noted:. This sheet shows the general operation of the term. The exact settings can vary according to software, builders and environments.

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