H3C Technologies H3C S12500 Series Switches - Manual (Page 210)

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Configuration considerations
Configure unambiguous QinQ termination to enable Layer 3 communication between Host A Host B
through VLAN interfaces. The following process briefly describes how unambiguous QinQ termination is
used for packet transmission between Host A and Host B:
1. When a packet from Host A is sent to Layer 3 Switch C by Layer 2 Switch B, it includes the outer
VLAN tag 100 and the inner VLAN tag 11.
2. When the packet arrives at VLAN-interface 100 on Layer 3 Switch C, the interface removes the
two VLAN tags before it forwards the packet at Layer 3.
3. When a packet from Host B arrives at Layer 3 Switch C, VLAN-interface 100 adds its interface
number as the outer VLAN tag to the packet. VLAN-interface 100 also adds the inner VLAN tag to
the packet if the inner VLAN ID specified by the second-dot1q command matches the VLAN ID that
is associated with the destination IP address of Host A in the ARP table. This example uses VLAN
11 as the inner VLAN tag.
4. On Layer 2 Switch B, GigabitEthernet 4/0/2 is a trunk port and the PVID is 100. When the packet
is received, the interface removes the outer VLAN tag and sends the single-tagged packet to Layer
2 Switch A.
Configuration procedure
1. Configure Host A and Host B:
{
Configure Host A's IP address as 1.1.1.1/24, and gateway IP address as 1.1.1.11/24.
{
Configure Host B's IP address as 1.1.2.1/24, and gateway IP address as 1.1.2.11/24.
2. Configure Layer 2 Switch A:
# Assign GigabitEthernet 3/0/2 to VLAN 11.
<L2_SwitchA> system-view
[L2_SwitchA] vlan 11
[L2_SwitchA-vlan11] port GigabitEthernet 3/0/2
[L2_SwitchA-vlan11] quit
# Configure GigabitEthernet 3/0/1 as a hybrid port and assign the port to VLAN 11 as a tagged
member.
[L2_SwitchA] interface GigabitEthernet 3/0/1
[L2_SwitchA-GigabitEthernet3/0/1] port link-type hybrid
[L2_SwitchA-GigabitEthernet3/0/1] port hybrid vlan 11 tagged
3. Configure Layer 2 Switch B:
# Configure GigabitEthernet 4/0/2 as a trunk port and assign the port to VLAN 100.
<L2_SwitchB> system-view
[L2_SwitchB] interface GigabitEthernet 4/0/2
[L2_SwitchB-GigabitEthernet4/0/2] port link-type trunk
[L2_SwitchB-GigabitEthernet4/0/2] port trunk permit vlan 100
# Configure VLAN 100 as the PVID of GigabitEthernet 4/0/2, enable QinQ on the port to add
outer VLAN tag 100 to the received packets.
[L2_SwitchB-GigabitEthernet4/0/2] port trunk pvid vlan 100
[L2_SwitchB-GigabitEthernet4/0/2] qinq enable
[L2_SwitchB-GigabitEthernet4/0/2] quit
# Configure GigabitEthernet 4/0/1 as a trunk port and assign the port to VLAN 100.
[L2_SwitchB] interface GigabitEthernet 4/0/1
[L2_SwitchB-GigabitEthernet4/0/1] port link-type trunk