Operation Manual

94
Port
PVID
Allowed VLANs
Port3
3
VLAN3
Table 6-4 Port settings before configuration synchronization
Port
PVID
Allowed VLANs
Port5
5
VLAN2, 3, 5
Port2
2
VLAN2, 5
Port3
3
VLAN2, 5
Table 6-5 Port settings after configuration synchronization
 MAC address duplication: After port configuration synchronization, packets from
Secondary VLAN can be forwarded via the promiscuous port untagged, and those from
Primary VLAN can be sent via the host port untagged. In order for these packets can be
forwarded in unicast via the right port, MAC address duplication is used to expand the
VLANs the MAC address is in. Normally, the egress ports for forwarding these packets
are identified through MAC address learning. For example the switch in
Figure 6-15
maintains a MAC address table shown in Table 6-6. The MAC address duplication
process has two aspects, that is, duplicating the dynamic MAC addresses learned by the
host ports in the secondary VLANs to the Primary VLAN and copying the dynamic MAC
addresses learned by the promiscuous ports in the Primary VLAN to the secondary
VLANs. As shown in
Figure 6-15, supposing the Router sends a packet with the source
MAC as mac_2 and the destination Mac as mac_a. The MAC address table on the switch
is changed to the one shown in Table 6-7.
Destination MAC
VLAN
Egress Port
mac_a
5
port 5
mac_2
2
port 2
mac_3
3
port 3
Table 6-6 MAC address table before duplication
Destination MAC
VLAN
Egress Port
mac_a
5
port 5
mac_a
2
port 5
mac_a
3
port 5
mac_2
2
port 2
mac_2
5
port 2
mac_3
3
port 3
mac_3
5
port 3
Table 6-7 MAC address table after duplication