H3C Technologies H3C S3100 Series Switches - Manual (Page 611)

Operation Manual – VLAN VPN
H3C S3100-52P Ethernet Switch Chapter 1 VLAN-VPN Configuration
1-7
# Add Ethernet1/0/1 port of Switch A to VLAN 10 and enable the VLAN-VPN function
for the port.
[SwitchA] interface Ethernet1/0/1
[SwitchA-Ethernet1/0/1] port access vlan 10
[SwitchA-Ethernet1/0/1] vlan-vpn enable
[SwitchA-Ethernet1/0/1] quit
2) Configure Switch B
Because Switch B comes from another manufacturer, the commands involved may
differ from those for S3100-52P switch. So only the operations are listed, as shown
below:
z
Configure Ethernet3/1/1 and Ethernet3/1/2 ports of Switch B to be trunk ports.
z
Add the two ports to VLAN 10.
Note:
The following describes how a packet is forwarded from Switch A to Switch C.
z
As the Ethernet1/0/1 port of Switch A is a VLAN-VPN port, when a packet from the
user’s network side reaches Ethernet1/0/1 port of Switch A, it is tagged with the
default VLAN tag of the port (VLAN 10) and is then forwarded to Ethernet1/0/2 port.
z
Because Ethernet1/0/2 port is configured with VLAN-VPN TPID, Switch A changes
the TPID value in the outer VLAN Tag of the packet to 0x9100 and forwards the
packet to the public network.
z
The packet reaches Ethernet3/1/2 port of Switch B in the public network. Switch B
forwards the packet to Ethernet3/1/1, which belongs to VLAN 10.
z
The packet is forwarded from Ethernet3/1/1 port of Switch B to the network on the
other side and enters Ethernet1/0/2 port of Switch C. Then Switch C forwards the
packet to its Ethernet1/0/1 port, which also belongs to VLAN 10. As Ethernet1/0/1
port is an access port, Switch C strips off the outer VLAN tag of the packet and
restores the original packet.
z
It is the same case when a packet travels from Switch C to Switch A.
After the configuration, the networks connecting Switch A and Switch C can receive
data packets from each other.