PLANET SGS-5220-24P2X User Manual
Page 114
User’s Manual of SGS-5220 Series
The Port VLAN is called an "Access VLAN" for ports in Access mode and Native
VLAN for ports in Trunk or Hybrid mode.
Port Type
Ports in hybrid mode allow for changing the port type, that is, whether a frame's
VLAN tag is used to classify the frame on ingress to a particular VLAN, and if so,
which TPID it reacts on. Likewise, on egress, the Port Type determines the TPID
of the tag, if a tag is required.
■
Unaware:
On ingress, all frames, whether carrying a VLAN tag or not, get classified
to the Port VLAN, and possible tags are not removed on egress.
■
C-Port:
On ingress, frames with a VLAN tag with TPID = 0x8100 get classified to
the VLAN ID embedded in the tag. If a frame is untagged or priority
tagged, the frame gets classified to the Port VLAN. If frames must be
tagged on egress, they will be tagged with a C-tag.
■
S-Port:
On ingress, frames with a VLAN tag with TPID = 0x8100 or 0x88A8 get
classified to the VLAN ID embedded in the tag. If a frame is untagged or
priority tagged, the frame gets classified to the Port VLAN. If frames must
be tagged on egress, they will be tagged with an S-tag.
■
S-Custom-Port:
On ingress, frames with a VLAN tag with a TPID = 0x8100 or equal to the
embedded in the tag. If a frame is untagged or priority tagged, the frame
gets classified to the Port VLAN. If frames must be tagged on egress, they
will be tagged with the custom S-tag.
Ingress Filtering
Hybrid ports allow for changing ingress filtering. Access and Trunk ports always
have ingress filtering enabled.
■
If ingress filtering is enabled (checkbox is checked), frames classified to a
VLAN that the port is not a member of get discarded.
■
If ingress filtering is disabled, frames classified to a VLAN that the port is
not a member of are accepted and forwarded to the switch engine.
However, the port will never transmit frames classified to VLANs that it is not a
member of.
Ingress Acceptance
Hybrid ports allow for changing the type of frames that are accepted on ingress.
■
Tagged and Untagged
Both tagged and untagged frames are accepted.
■
Tagged Only
Only tagged frames are accepted on ingress. Untagged frames are
discarded.
■
Untagged Only
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