Zyxel IES-5112 [595/1156] Tagged frames forwarding example

Zyxel IES-5106 [595/1156] Tagged frames forwarding example
Chapter 16 VLAN Screens
Management Switch Card User’s Guide
595
16.3.2 GVRP
GVRP (GARP VLAN Registration Protocol) is a registration protocol that defines a way for switches to
register necessary VLAN members on ports across the network. Enable this function to permit
VLANs groups beyond the local switch.
Please refer to the following table for common IEEE 802.1Q VLAN terminology.
16.4 Tagged Frames Forwarding Example
1 First the MSC checks the VLAN ID (VID) of tagged frames or assigns temporary VIDs to untagged
frames.
2 The MSC then checks the VID in a frame’s tag against the SVLAN table.
3 The MSC notes what the SVLAN table says (that is, the SVLAN tells the MSC whether or not to
forward a frame and if the forwarded frames should have a tag).
4 Then the MSC 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.
16.5 Untagged Frames Forwarding Example
1 An untagged frame comes in from the LAN.
Table 324 IEEE 802.1Q VLAN Terminology
VLAN PARAMETER TERM DESCRIPTION
VLAN Type Permanent VLAN This is a static VLAN created manually.
Dynamic VLAN This is a VLAN configured by a GVRP registration/deregistration
process.
VLAN Administrative
Control
Registration Fixed Fixed registration ports are permanent VLAN members.
Registration
Forbidden
Ports with registration forbidden are forbidden to join the
specified VLAN.
Normal Registration Ports dynamically join a VLAN using GVRP.
VLAN Tag Control Tagged Ports belonging to the specified VLAN tag all outgoing frames
transmitted.
Untagged Ports belonging to the specified don't tag all outgoing frames
transmitted.
VLAN Port Port VID This is the VLAN ID assigned to untagged frames that this port
received.
Acceptable Frame
Type
You may choose to accept both tagged and untagged incoming
frames or just tagged incoming frames on a port.
Ingress Filtering If set, the switch discards incoming frames for VLANs that do not
have this port as a member

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