H3C S7500 Series Operation Manual page 128

Operation Manual – Extended VLAN Application
H3C S7500 Series Ethernet Switches
II. Configure Switch A
To ensure that packets coming from Switch A can be forwarded by Switch B according
to the VLAN configurations of the lower layer devices, you need to configure the port
through which Switch A connects to Switch B to remove VLAN tags when Switch A
sends packets to Switch B.
Switch A Switch A Switch A Switch A Switch A Switch A Switch A Switch A Switch A Switch A Switch A Switch A Switch A Switch A Switch A
E1/0/1 E1/0/1 E1/0/1 E1/0/1
E1/0/4 E1/0/4 E1/0/4 E1/0/4
VLAN3 VLAN3
Figure 2-1 Diagram for isolate-user-VLAN applicatio
III. Forward packets to Switch A
1) When packets sent by PC reaches Ethernet 1/0/4, the default VLAN ID, that is, the
VLAN tag of VLAN 3 is automatically added to the packets.
2) Switch B learns the MAC address of the PC, and adds it to the MAC address
forwarding table of VLAN 3, and at the same time copies the entry to the MAC
address forwarding table of VLAN 5.
3) Because Ethernet 1/0/1 belongs to VLAN 3, Ethernet 1/0/1 can forward the
packets from VLAN 3 and automatically removes the tag of VLAN 3, so that
packets reaching Switch A is without the VLAN tag.
IV. Receive and forward packets from Switch A
1) When packets coming from Switch A (the packets are without VLAN tag through
certain configuration) reach to port Ethernet 1/0/1 of Switch B, the packets are
automatically added with default VLAN ID, that is, the tag of VLAN 5.
2) According to the MAC address forwarding table copied in the outbound process,
the system will find the egress port being Ethernet 1/0/4.
3) Because Ethernet 1/0/4 belongs to VLAN 5, packets can pass through it normally,
and at the same time, Ethernet 1/0/4 removes the VLAN tag of the packets. So
that the PC receives packets without VLAN tag.
Switch B Switch B Switch B Switch B Switch B Switch B Switch B Switch B
Isolate-user Isolate-user -VLAN 5 Isolate-user Isolate-user Isolate-user Isolate-user -VLAN 5 Isolate-user Isolate-user 5 5 5 5 5 5
Chapter 2 Isolate-User-VLAN Configuration
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