•Enter forbidden to block a
•Enter no fixed or no forbidden to change
•Enter untagged to send outgoing frames without a tag.
•Enter no untagged to tag outgoing frames.
42.5.4.1Modify a Static VLAN Table Example
The following example configures ports 1 to 5 as fixed and untagged ports in VLAN 2000.
Figure 201 Modifying Static VLAN Example
ras (config)# vlan 2000
ras
42.5.4.2 Forwarding Process Example
Tagged 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.
Untagged Frames
1An untagged frame comes in from the LAN.
2The switch checks the PVID table and assigns a temporary VID of 1.
3The switch ignores the port from which the frame came, because the switch does not send a frame to the port from which it came. The switch also does not forward frames to “forbidden” ports.
4If after looking at the SVLAN, the switch does not have any ports to which it will send the frame, it won’t check the port filter.
42.5.5Delete VLAN ID
Syntax:
no vlan
Chapter 42 IEEE 802.1Q Tagged VLAN Commands | 294 |