Introduction to VLAN Port Configuration

This document is going to introduce what the VLAN Port Configuration, such as ingress rule, egress rule, port type, frame type, and PVID, will do on the incoming and outgoing frames based on VigorSwitch P2261.

When the frame enters the switch

1. Check if the frame is tagged

Frame Type setting determines whether the traffic should be accepted or discarded according to whether it is tagged or not.

• All: accept both tagged and untagged frames
• Tagged: only accept tagged frames, discard the untagged frames.
• Untagged: only accept untagged frames, discard the tagged frames.

2. Check the TPID of the frame

Port Type setting determines whether the switch should accept or discard a frame according to the Tag Protocol Identifier (TPID) of it. Below are the options of Port Type.

• Unaware: Accept frames with any TPID.
• C-port: Discard frames with TPID is 0x88a8, accept TPID 0x8100 (which is the protocol which Vigor Router uses) and others.
• S-port: Discard frames with TPID 0x8100 (which is the protocol which Vigor Router uses), accept the others.
• S-custom-port: Accept frame with TPID 0x8100 or 0x88a8, discard the others.

3. Check the VID of the frame

Ingress Filtering setting determines whether this frame should be accepted or discarded according to the VLAN Identifier (VID).

• Disable: Accept frames with any VID.
• Enable: Accept the frame if its VID is one of the VLAN that this port belongs. Discard the frame if the port is not a member of the VLAN with which this frame is associated. 

Before forwarding the frame to other ports

Before the switch sends out the frame, Port Type setting determines whether to add a tag to the frame or not.

• Unaware: any frames will be added a tag (VID= PVID) and then forwarded.
• C-port: If the frame's TPID is 0x8100 (which is Vigor Router uses), it will be forwarded without adding a tag. If the frame is untagged or with TPID other than 0x88a8, the switch will a tag (VID= PVID) to it and then forwarded.
• S-port: Discard frames with TPID 0x8100 (which is the protocol which Vigor Router uses), and forward the others without adding a tag.
• S-custom-port: If the frame's TPID is 0x8100 (which is Vigor Router uses), it will be forwarded without adding a tag. If the frame is untagged, the switch will add a tag to it (VID= PVID) and then forward it.

Before the frame leaves the switch

Egress Rule determines whether the tag should be removed or not before the frame leaves the port. There are three options for Egress Rule:

• Hybrid: remove the tag if the frame's VID is the same as PVID, keep the tag if it's not.
• Trunk: keep all the tags.
• Access: Remove all the tags.