Chapter 34 IEEE 802.1Q Tagged VLAN Commands

Syntax:

vlan <vlan-id> fixed <port-list> forbidden <port-list> name <name-str> normal <port-list> untagged <port-list> no fixed <port-list>

no forbidden <port-list> no untagged <port-list>

where

<vlan-id>

=

The VLAN ID [1 – 4094].

<name-str>

=

A name to identify the SVLAN entry.

<port-list> =

This is the switch port list.

•Enter fixed to register the <port-list>to the static VLAN table with <vlan-id>.

•Enter normal to confirm registration of the <port-list>to the static VLAN table with

<vlan-id>.

•Enter forbidden to block a <port-list>from joining the static VLAN table with

<vlan-id>.

•Enter no fixed or no forbidden to change <port-list>to normal status.

•Enter untagged to send outgoing frames without a tag.

•Enter no untagged to tag outgoing frames.

The following example configures ports 1 to 5 as fixed and untagged ports in VLAN 2000.

sysname(config)# vlan 2000 sysname(config-vlan)# fixed 1-5 sysname(config-vlan)# untagged 1-5

34.3.5 Forwarding Process Example

34.3.5.1Tagged Frames

1First the switch checks the VLAN ID (VID) of tagged frames or assigns temporary VIDs to untagged frames.

2The switch then checks the VID in a frame’s tag against the SVLAN table.

3The switch notes what the SVLAN table says (that is, the SVLAN tells the switch whether or not to forward a frame and if the forwarded frames should have tags).

4Then the switch applies the port filter to finish the forwarding decision. This means that frames may be dropped even if the SVLAN says to forward them. Frames might also be dropped if they are sent to a CPE (customer premises equipment) DSL device that does not accept tagged frames.

34.3.5.2Untagged Frames

1An untagged frame comes in from the LAN.

2The switch checks the PVID table and assigns a temporary VID of 1.

 

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VES-1616F-3x Series User’s Guide