Pass-Through Domain Processing - Lenovo Flex System Fabric CN4093 Application Manual

Pass-Through Domain Processing

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Pass‐through domain processing is the default operating mode for SPAR when
performing L2 switching based on an outer tag.
In pass‐through processing mode, each SPAR is identified by its unique VLAN
domain ID. Packets are classified based on the SPAR domain ID (outer tag). SPAR
ports must be configured in tunnel mode.
SPAR provides single or multiple VLAN connectivity through a single uplink port
or LAG (static or LACP). VLAN definition within the SPAR domain is not
required.
Pass‐through domain operates in Q‐In‐Q mode. Inside SPAR, different
user‐defined VLAN traffic is classified into single S‐VLAN (service VLAN)
associated with the SPAR.
Although the uplink can be shared by multiple networks using the pass‐through
domain, SPAR will not be server‐VLAN aware. Hence, multiple VLAN traffic will
be mixed together in a single broadcast domain, that is, broadcast traffic on
different VLANs from the upstream network will reach all servers attached to the
SPAR pass‐through domain. The servers drop the packets if they do not belong to
the desired VLAN. The pass‐through implementation uses ingress VLAN tagging,
that is, tagpvid‐ingress is enabled on all SPAR ports.
In pass‐through domain processing mode, all SPAR ports must have the following
settings:
PVID/Native VLAN tagging is disabled.

 Ingress VLAN tagging is enabled on all SPAR ports.
PVID/Native VLAN is based on the SPAR DVLAN.

CN 4093(config)# interface port <num>
CN 4093(config-if)# switchport trunk native vlan <VLAN number>
Chapter 22: Switch Partition
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