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Everything networking - What is a trunk port in a VLAN network?

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SAT Norte Europa
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A trunk port in a VLAN network is a port configured to carry traffic for multiple VLANs over a single network link. This is essential for connecting switches and routers that need to communicate across different VLANs. Here are some key points:

  • VLAN Tagging: Trunk ports use VLAN tagging protocols like 802.1Q to identify and manage the VLANs. Each packet passing through a trunk port is tagged with a VLAN ID.
  • Inter-VLAN Communication: Trunk ports facilitate communication between devices on different VLANs, ensuring efficient data flow and network segmentation.
  • Network Design: Trunk ports help reduce the number of physical links needed, simplifying network design and lowering costs.

How to configure VLAN for default port in Reyee EG router?

1. Add a new VLAN port on LAN settings.
VLAN1.png2. Configure the port based on the VLAN
VLAN2.png

VLAN3.png


3. Some items for port VLAN
(1) To configure port VLAN, need to add the VLAN interface first
a)When adding vlan to the lan port, the range of vlan is 2-232, 234-4090
b)VLAN233 is occupied by default, this VLAN cannot be configured
(2) There are 3 options in each port: TAG, UNTAG, and not Join
a)For port 0, the UNTAG of the default VLAN cannot be modified
b)For other ports, only one vlan can be set to UNTAG and can be multiple TAG and NotJoin


UNTAG：The port does not carry the vlan tag when sending the packets, similar to the native vlan configuration of the switch

TAG: The packets corresponding to the VLAN sent from the port will carry the VLAN tag, similar to the non-native VLAN of the trunk port

NotJoin：The port does not belong to the vlan and does not participate in the forwarding of the vlan packet, which is removing the vlan when configuring to allow vlan under the trunk

 

Sure, let's break it down into simpler terms:

VLAN Tagging Explained

  1. UNTAG:
    • What it means: When a port sends packets, it doesn't add any VLAN tags to them.
    • Analogy: Think of it like sending a letter without any special markings. It's just a regular letter.
    • Use case: This is similar to the "native VLAN" on a switch, where packets are sent without any VLAN identification.
  2. TAG:
    • What it means: When a port sends packets, it adds a VLAN tag to each packet.
    • Analogy: Imagine sending a letter with a special stamp that identifies it as part of a specific group.
    • Use case: This is like the "non-native VLAN" on a trunk port, where packets are tagged to show which VLAN they belong to.
  3. NotJoin:
    • What it means: The port is not part of the VLAN and doesn't handle packets for that VLAN.
    • Analogy: It's like a mailbox that doesn't accept letters from a certain group.
    • Use case: This is used when configuring which VLANs are allowed on a trunk port, effectively removing the VLAN from the port's responsibilities.

Does this help clarify things? Feel free to ask if you have more questions!

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