LevelOne GSW-4876 - Manual (Page 171)

C HAPTER 4 | Configuring the Switch
IEEE 802.1Q VLANs
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◆ Port Type – Configures how a port processes the VLAN ID in ingress
frames. (Default: Unaware)
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C-port – For customer ports, each frame is assigned to the VLAN
indicated in the VLAN tag, and the tag is removed.
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S-port – For service ports, the EtherType of all received frames is
changed to 0x88a8 to indicate that double-tagged frames are being
forwarded across the switch. The switch will pass these frames on
to the VLAN indicated in the outer tag. It will not strip the outer tag,
nor change any components of the tag other than the EtherType
field.
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S-custom-port – For custom service ports, the EtherType of all
received frames is changed to value set in the Ethertype for Custom
S-ports field to indicate that double-tagged frames are being
forwarded across the switch. The switch will pass these frames on
to the VLAN indicated in the outer tag. It will not strip the outer tag,
nor change any components of the tag other than the EtherType
field.
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Unaware – All frames are classified to the Port VLAN ID and tags
are not removed.
◆ Ingress Filtering - Determines how to process frames tagged for
VLANs for which the ingress port is not a member. (Default: Disabled)
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Ingress filtering only affects tagged frames.
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If ingress filtering is enabled and a port receives frames tagged for
VLANs for which it is not a member, these frames will be discarded.
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If ingress filtering is disabled and a port receives frames tagged for
VLANs for which it is not a member, these frames will be flooded to
all other ports.
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Ingress filtering does not affect VLAN independent BPDU frames,
such as GVRP or STP. However, they do affect VLAN dependent
BPDU frames, such as GMRP.
◆ Frame Type - Sets the interface to accept all frame types, including
tagged or untagged frames, only tagged frames, or only untagged
frames. When set to receive all frame types, any received frames that
are untagged are assigned to the default VLAN. When set to receive
only tagged frames, all untagged frames received on the interface are
discarded. (Option: All, Tagged, Untagged; Default: All)
◆ Port VLAN Mode - Determines how to process VLAN tags for ingress
and egress traffic. (Options: None, Specific; Default: Specific)
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None - The ID for the VLAN to which this frame has been assigned
is inserted in frames transmitted from the port. The assigned VLAN
ID can be based on the ingress tag for tagged frames, or the default
PVID for untagged ingress frames. Note that this mode is normally
used for ports connected to VLAN-aware switches.
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Specific - A Port VLAN ID can be configured (as described below).
Untagged frames received on the port are classified to the Port
VLAN ID. If Port Type is Unaware, all frames received on the port