Step 4: Create the interface to enable proxy ARP

To create the TCP/IP interface to enable proxy ARP, complete these steps:

  1. Obtain a contiguous block of IP addresses that are routable by your network.

    Since you have two partitions in this virtual Ethernet, you need a block of four addresses. The fourth segment of the first IP address in the block must be divisible by four. The first and last IP addresses of this block are the subnet and broadcast IP addresses are unusable. The second and third IP address can be used for the TCP/IP interfaces for the virtual Ethernet on partition A and partition B. For this procedure, the IP address block is 10.1.1.72 through 10.1.1.75 with a subnet mask of 255.255.255.252.

    You also need a single IP address for your external TCP/IP address. This IP address does not have to belong to your block of contiguous addresses, but it must be within the same original subnet mask of 255.255.255.0. In this procedure, the external IP address is 10.1.1.15.

  2. Create an i5/OS™ TCP/IP interface for partition B. This interface is known as the external, proxy ARP IP interface. To create the interface, follow these steps:
    1. On the command line on partition B, type CFGTCP, and then press Enter to see the Configure TCP/IP panel.
    2. Select option 1 (Work with TCP/IP Interfaces), and then press Enter.
    3. Select option 1 (Add), and then press Enter to see the Add TCP/IP Interface (ADDTCPIFC) panel.
    4. At the Internet address prompt, type '10.1.1.15'.
    5. At the Line description prompt, type the name of your line description, such as ETHLINE.
    6. At the Subnet mask prompt, type '255.255.255.0'.
  3. Start the interface. On the Work with TCP/IP Interfaces panel, select option 9 (Start) by the interface.
Parent topic: Proxy Address Resolution Protocol method
Previous topic: Step 3: Turn on IP datagram forwarding
Next topic: Step 5: Create the virtual TCP/IP interface on partition A