3Com S7906E - Switch, Configuration Manual

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1-5
Many-to-one VLAN mapping
On the downlink port On the uplink port
For uplink traffic For downlink traffic
Do... Based on… Do... Based on…
Map all specified
customer VLANs
(CVLAN) to one
service provider
VLAN (SVLAN)
Uplink policy in the
inbound direction
Replace the SVLAN
with the original
CVLAN
DHCP snooping
address table, which
contains mappings of
the SVLAN, IP
address, MAC
address, and CVLAN
for DHCP clients
One-to-two VLAN mapping
On the downlink port
For uplink traffic For downlink traffic
Do... Based on… Do... Based on…
Tag the
CVLAN-tagged
traffic with the
SVLAN
Uplink policy in the
inbound direction
Forward traffic with the
outer VLAN tag (the
SVLAN) removed
You need to configure
the downlink port as a
hybrid port to forward
SVLAN frames with the
outer VLAN tag
removed.
Two-to-two VLAN mapping
In two-to-two VLAN mapping, the outer VLAN and the inner VLAN carried in a double-tagged uplink
frame received at the downlink port on the edge device of an SP network are called the original SVLAN
and CVLAN, and the VLANs that the edge device substitutes for the original SVLAN and CVLAN are
called the new SVLAN and CVLAN.