Planet IGS-20040MT User Manual page 123

Hybrid

Port VLAN

Port Type

By default, a trunk port is member of all VLANs (1-4095)

The VLANs that a trunk port is member of may be limited by the use of
Allowed VLANs

Frames classified to a VLAN that the port is not a member of are
discarded

By default, all frames but frames classified to the Port VLAN (a.k.a.
Native VLAN) get tagged on egress. Frames classified to the Port
VLAN do not get C-tagged on egress

Egress tagging can be changed to tag all frames, in which case only
tagged frames are accepted on ingress
Hybrid ports resemble trunk ports in many ways, but adds additional port
configuration features. In addition to the characteristics described for trunk ports,
hybrid ports have these abilities:

Can be configured to be VLAN tag unaware, C-tag aware, S-tag
aware, or S-custom-tag aware

Ingress filtering can be controlled

Ingress acceptance of frames and configuration of egress tagging can
be configured independently
Determines the port's VLAN ID (PVID). Allowed VLANs are in the range 1
through 4095, default being 1.
■ On ingress, frames get classified to the Port VLAN if the port is configured as
VLAN unaware, the frame is untagged, or VLAN awareness is enabled on
the port, but the frame is priority tagged (VLAN ID = 0).
■ On egress, frames classified to the Port VLAN do not get tagged if Egress
Tagging configuration is set to untag Port VLAN.
The Port VLAN is called an "Access VLAN" for ports in Access mode and Native
VLAN for ports in Trunk or Hybrid mode.
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:
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User's Manual of IGS-20040MT