Figure 31-4 Svlan Example - ZyXEL Communications IES-1000 User Manual

IES-1000 User's Guide

Figure 31-4 SVLAN Example

An untagged frame comes in from the LAN.
The switch checks the PVID table and assigns a temporary VID of 1.
The switch ignores port# 1 (the LAN port where the frame came in), because the switch does not send a frame to
the port that it came in through.
The switch sees that port #s 2, 3, 4, 6, 7 and 9 (DSL ports 1, 2, 3, 5, 6 and 8) are all set to "fixed" and "untag"
which means the SVLAN allows the frame to be sent to those ports without a tag.
Port # 5 is "forbidden" so the frame is not forwarded to DSL port # 4.
Port # 7 (DSL port 6) is "normal" which means that it was entered dynamically, so the frame is permitted to be
forwarded to port # 7 if port # 7 is registered in the DVLAN table.
After looking at the SVLAN, the switch sees that the port filter is set for port 1 (the LAN port) to forward frames
to all of the ADSL ports, so the switch forwards everything that the SVLAN permits.
Please note that the switch also sends the frame to "CPU" (the switch itself), because the switch is a member of
this VLAN. The switch can be a member of only one VLAN at a time.
IEEE 802.1Q Tagged VLAN Commands 31-7