Alloy AS5010-P, User Manual

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AS Series User Manual
196
Doc No.: AS5-0116-01
C-Port:
C-Ports is the more commonly used port type for VLAN for Tagged ports.
We recommend using this Port type for Tagged VLANs unless you are a service
provider or require QinQ stacked VLAN’s.
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:
S-Ports are used for provider bridging (also known as QinQ, stacked VLANs, or
double tagging).
QinQ is used when a customer has to transport VLAN tagged traffic across a
service provider network. The service provider will have its own set of VLAN
tags, such as a tag per customer.
S-TAGs are correlated with the 0x88a8 TPID to signify the existence of the inner
C-TAG which uses TPID 0x8100 (S-TAGs are inserted before C-TAGs).
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
Ethertype configured for Custom-S ports 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 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.
VLAN Trunking
Trunk and Hybrid ports allow for enabling VLAN trunking.
When VLAN trunking is enabled, frames classified to unknown VLANs are
accepted on the port whether ingress filtering is enabled or not.
This is useful in scenarios where a cloud of intermediary switches must bridge