Configuration example for QinQ termination supporting DHCP relay

As shown in Figure 9:

• Provider A and Provider B are edge devices on the service provider network.

• DHCP client A and DHCP client B are devices on the customer networks.

• Provider A is the DHCP relay agent. Provider B is the DHCP server.

• Provider A and Provider B communicate with each other through Layer 3 interfaces.

Configure QinQ termination on Provider A so that DHCP client A and DHCP client B can obtain IP settings from Provider B.

1. Configure the DHCP relay agent Provider A:

   # Enable DHCP service.

   <ProviderA> system-view
   [ProviderA] dhcp enable
   

   # Create a Layer 3 Ethernet subinterface GigabitEthernet 1/0/1.100.

   [ProviderA] interface gigabitethernet 1/0/1.100
   

   # Configure GigabitEthernet 1/0/1.100 to terminate packets whose Layer 1 ID is 100 and Layer 2 VLAN ID is 10 or 20.

   [ProviderA-GigabitEthernet1/0/1.100] vlan-type dot1q vid 100 second-dot1q 10 20
   

   # Enable GigabitEthernet 1/0/1.100 to transmit broadcast and multicast packets.

   [ProviderA-GigabitEthernet1/0/1.100] vlan-termination broadcast enable
   

   # Enable DHCP relay on GigabitEthernet 1/0/1.100 and specify 10.2.1.1 as the DHCP server address.

   [ProviderA-GigabitEthernet1/0/1.100] dhcp select relay
   [ProviderA-GigabitEthernet1/0/1.100] dhcp relay server-address 10.2.1.1
   

   # Assign an IP address to GigabitEthernet 1/0/1.100.

   [ProviderA-GigabitEthernet1/0/1.100] ip address 192.168.1.1 24
   [ProviderA-GigabitEthernet1/0/1.100] quit
   

   # Enable recording of relay entries on the relay agent.

   [ProviderA] dhcp relay client-information record
   

   # Assign an IP address to the interface Serial 2/1/0.

   [ProviderA] interface serial 2/1/0
   [ProviderA-Serial2/1/0] ip address 10.1.1.1 24
   [ProviderA-Serial2/1/0] quit
   

   # Configure a static route to the DHCP server.

   [ProviderA] ip route-static 10.2.1.1 24 10.1.1.1
   

2. Configure the DHCP server Provider B:

   # Assign an IP address to the DHCP server.

   <ProviderB> system-view
   [ProviderB] interface serial 2/1/0
   [ProviderB-Serial2/1/0] ip address 10.2.1.1 24
   [ProviderB-Serial2/1/0] quit
   

   # Enable DHCP.

   [ProviderB] dhcp enable
   

   # Configure an IP address pool on the DHCP server.

   [ProviderB] dhcp server ip-pool 1
   [ProviderB-dhcp-pool-1] network 192.168.1.0 24
   [ProviderB-dhcp-pool-1] gateway-list 192.168.1.1
   [ProviderB-dhcp-pool-1] quit
   

   # Configure a static route to GigabitEthernet 1/0/1.100.

   [ProviderB] ip route-static 192.168.1.1 24 10.1.1.1
   

3. Configure Switch A:

   # Configure the uplink port GigabitEthernet 1/0/1 as a trunk port, and assign the port to VLAN 100.

   <SwitchA> system-view
   [SwitchA] interface gigabitethernet 1/0/1
   [SwitchA-GigabitEthernet1/0/1] port link-type trunk
   [SwitchA-GigabitEthernet1/0/1] port trunk permit vlan 100
   [SwitchA-GigabitEthernet1/0/1] quit
   

   # Configure the downlink port GigabitEthernet 1/0/2 as a trunk port, and assign the port to VLANs 10 and 100.

   [SwitchA] interface gigabitethernet 1/0/2
   [SwitchA-GigabitEthernet1/0/2] port link-type trunk
   [SwitchA-GigabitEthernet1/0/2] port trunk permit vlan 10 100
   

   # Set the PVID of GigabitEthernet 1/0/2 to VLAN 100.

   [SwitchA-GigabitEthernet1/0/2] port trunk pvid vlan 100
   

   # Enable QinQ on GigabitEthernet1/0/2.

   [SwitchA-GigabitEthernet1/0/2] qinq enable
   [SwitchA-GigabitEthernet1/0/2] quit
   

   # Configure the downlink port GigabitEthernet 1/0/3 as a trunk port, and assign the port to VLANs 20 and 100.

   [SwitchA] interface gigabitethernet 1/0/3
   [SwitchA-GigabitEthernet1/0/3] port link-type trunk
   [SwitchA-GigabitEthernet1/0/3] port trunk permit vlan 20 100
   

   # Set the PVID of GigabitEthernet 1/0/3 to VLAN 100.

   [SwitchA-GigabitEthernet1/0/3] port trunk pvid vlan 100
   

   # Enable QinQ on GigabitEthernet 1/0/3.

   [SwitchA-GigabitEthernet1/0/3] qinq enable
   [SwitchA-GigabitEthernet1/0/3] quit
   

   # Assign GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 to VLAN 100.

   [SwitchA] vlan 100
   [SwitchA-vlan100] port gigabitethernet 1/0/2
   [SwitchA-vlan100] port gigabitethernet 1/0/3
   

4. Configure Switch B:

   # Create VLAN 10.

   <SwitchB> system-view
   [SwitchB] vlan 10
   

   # Assign GigabitEthernet 1/0/2 to VLAN 10.

   [SwitchB-vlan10] port gigabitethernet 1/0/2
   [SwitchB-vlan10] quit
   

   # Configure GigabitEthernet 1/0/1 as a trunk port, and assign the port to VLAN 10.

   [SwitchB] interface gigabitethernet 1/0/1
   [SwitchB-GigabitEthernet1/0/1] port link-type trunk
   [SwitchB-GigabitEthernet1/0/1] port trunk permit vlan 10
   

5. Configure Switch C:

   # Create VLAN 20.

   <SwitchC> system-view
   [SwitchC] vlan 20
   

   # Assign GigabitEthernet 1/0/2 to VLAN 20.

   [SwitchC-vlan20] port gigabitethernet 1/0/2
   [SwitchC-vlan20] quit
   

   # Configure GigabitEthernet 1/0/1 as a trunk port, and assign the port to VLAN 20.

   [SwitchC] interface gigabitethernet 1/0/1
   [SwitchC-GigabitEthernet1/0/1] port link-type trunk
   [SwitchC-GigabitEthernet1/0/1] port trunk permit vlan 20
   

# Verify that DHCP client A and DHCP client B can obtain IP settings from Provider B. (Details not shown.)