Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 311)

Multi-Service IronWare Switching Configuration Guide 281
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Backbone Edge Bridge (BEB) operation
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Example 3:
If the packet is destined to an IB-Tagged endpoint, the original tag that contains the C-VID of
100 is stripped at ingress and a PBB header (contains the B-MACs, B-Tag and I-Tag) is inserted
when the packet exits through the IB-Tagged endpoint. Optionally, if S-VLAN keep mode is
configured, an S-Tag will also be inserted. More details about S-VLAN keep mode is discussed
in a later section.
S-Tagged endpoint
S-Tagged endpoint is defined as an endpoint that considers all packets received with the top most
tag being the Service provider Tag (S-Tag). The user must configure the Ethernet Type value of the
port to match the S-Tag TPID value of the packets received on the specified port. The packet
processing operation whether it is S-Tagged or C-Tagged is equivalent. When flooding is performed,
a valid packet received through the S-Tagged endpoint will be flooded to all endpoints configured
under the same SI, regardless of the egress endpoint tag type.
Dual-tagged endpoint
Dual-tagged endpoint is defined as an endpoint that expects two tags (Q-in-Q) where the top most
tag must match the configured Ethernet Type value of the port and the inner tag must match the
default TPID of 0x8100. The dual-tagged endpoint configuration is NOT supported with PBB on
Brocade NetIron XMR and Brocade MLX series.
IB-Tagged Endpoint
An IB-Tagged endpoint represents all frames on a physical port with a particular B-VID and a
particular I-SID. When such a packet is received from the IB-endpoint destined to another local
endpoint of the same PBB instance, the PBB header will be stripped and a destination tag may be
inserted accordingly based on the exiting endpoint configuration.
Example 1:
If the packet is destined to a C-Tagged endpoint with C-VID 100, the original PBB header is
stripped and a C-Tag with C-VID 100 is inserted as the packet exits the C-tagged endpoint. The
TPID value will be configured for the Ethernet type value of the exit port.
Example 2:
If the packet is destined to an S-Tagged endpoint with S-VID 300, the original PBB header is
stripped and an S-Tag with S-VID 300 is inserted as the packet exit the S-tagged endpoint. The
TPID value will be configured for the Ethernet type value of the exit port.
Example 3:
If the packet is destined to a port based untagged endpoint, the original PBB header is
stripped. No additional tag will be inserted as the packet exit the untagged endpoint.
Example 4:
If the packet is destined to another IB-Tagged endpoint with the same B-VID and ISID value of
the received PBB frame, the original PBB frame is NOT touched (the PBB header remains
unchanged) and will be send out towards the specified outgoing interface as determined by
the BEB’s switching logic.