Procedure

1. Configure the DHCP relay on SwitchA.

   # Add the interface to the VLAN.

   <HUAWEI> system-view[HUAWEI] sysname SwitchA[SwitchA] vlan batch 100 200[SwitchA] interface gigabitethernet 0/0/1[SwitchA-GigabitEthernet0/0/1] port link-type trunk[SwitchA-GigabitEthernet0/0/1] port trunk allow-pass vlan 200[SwitchA-GigabitEthernet0/0/1] quit[SwitchA] interface gigabitethernet 0/0/2[SwitchA-GigabitEthernet0/0/2] port link-type access[SwitchA-GigabitEthernet0/0/2] port default vlan 100[SwitchA-GigabitEthernet0/0/2] quit[SwitchA] interface vlanif 200 [SwitchA-Vlanif200] ip address 192.168.20.1 24[SwitchA-Vlanif200] quit

   # Enable the DHCP relay function on the interface.

   [SwitchA] dhcp enable  //Enable the DHCP service. By default, the service is disabled.[SwitchA] interface vlanif 100[SwitchA-Vlanif100] ip address 10.10.20.1 24[SwitchA-Vlanif100] dhcp select relay   //Enable the DHCP relay function. By default, the function is disabled.[SwitchA-Vlanif100] dhcp relay server-ip 192.168.20.2  //Configure the DHCP server IP address for the DHCP relay agent.[SwitchA-Vlanif100] quit

2. Configure the DHCP server function based on the global address pool on SwitchB.

   # Enable the DHCP service. By default, the service is disabled.

   <HUAWEI> system-view[HUAWEI] sysname SwitchB[SwitchB] dhcp enable

   # Configure VLANIF 200 to work in global address pool mode.

   [SwitchB] vlan 200 [SwitchB-vlan200] quit[SwitchB] interface gigabitethernet 0/0/1[SwitchB-GigabitEthernet0/0/1] port link-type trunk[SwitchB-GigabitEthernet0/0/1] port trunk allow-pass vlan 200[SwitchB-GigabitEthernet0/0/1] quit[SwitchB] interface vlanif 200 [SwitchB-Vlanif200] ip address 192.168.20.2 24[SwitchB-Vlanif200] dhcp select global  //Enable the DHCP server function based on the global address pool on the interface. By default, the function is disabled.[SwitchB-Vlanif200] quit

   # Create an address pool and configure the attributes. The default lease (one day) is used and does not need to be configured.

   [SwitchB] ip pool pool1[SwitchB-ip-pool-pool1] network 10.10.20.0 mask 24  //Configure the network segment and mask of the global address pool.[SwitchB-ip-pool-pool1] gateway-list 10.10.20.1  //Configure the gateway address assigned to the terminals.[SwitchB-ip-pool-pool1] quit

3. Configure static routes to the terminals on SwitchB.

   [SwitchB] ip route-static 10.10.20.0 255.255.255.0 192.168.20.1 

4. Configure each terminal (using the PC running Windows 7 as an example) to automatically obtain an IP address.
   1. Right-click Network and choose Properties to display the Network and Sharing Center window.
   2. Click Local Area Connection to display the Local Area Connection Status window.
   3. Click Properties to display the Local Area Connection Properties window.
   4. Select Internet Protocol Version 4 (TCP/IPv4) and click Properties to display the Internet Protocol Version 4 (TCP/IPv4) Properties window. Select Obtain an IP address automatically, and click OK.

5. Verify the configuration.

   # Run the display dhcp relay interface vlanif 100 command on SwitchA to check the DHCP relay configuration.

   [SwitchA] display dhcp relay interface vlanif 100
    DHCP relay agent running information of interface Vlanif100 : 
    Server IP address [00] : 192.168.20.2
    Gateway address in use : 10.10.20.1

   # Run the display ip pool command on SwitchB to check the IP address allocation of pool1. For example, the enterprise has 100 terminals. The following uses the command output in V200R011C10 as an example.

   [SwitchB] display ip pool name pool1
     Pool-name        : pool1
     Pool-No          : 0
     Lease            : 1 Days 0 Hours 0 Minutes
     Domain-name      : -
     DNS-server0      : -               
     NBNS-server0     : -               
     Netbios-type     : -               
     Position         : Local           
     Status           : Unlocked
     Gateway-0        : 10.10.20.1      
     Network          : 10.10.20.0
     Mask             : 255.255.255.0
     VPN instance     : --
     Logging          : Disable
     Conflicted address recycle interval: -
     Address Statistic: Total       :253       Used        :1          
                        Idle        :252       Expired     :0          
                        Conflict    :0         Disabled    :0      
   
    -------------------------------------------------------------------------------
     Network section 
            Start           End       Total    Used Idle(Expired) Conflict Disabled
    -------------------------------------------------------------------------------
         10.10.20.1    10.10.20.254     253       1        252(0)       0     0
    -------------------------------------------------------------------------------