Proxy Address Resolution Protocol method

 

This proxy Address Resolution Protocol (ARP) method uses transparent subnetting to associate a partition's virtual interface with an external interface.

The proxy ARP function is built into the TCP/IP stack. It is suggested that you use this method if you have the necessary IP addresses.

You might want to learn more information about transparent subnetting:

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If you choose to use the proxy ARP method, have a firm understanding of subnetting and TCP/IP. You need to obtain a contiguous block of IP addresses that are routable by your network. You subnet this block of IP addresses. In this example, a contiguous block of four IP addresses (10.1.1.72 through 10.1.1.75) is used. Because it is a block of four IP addresses, the subnet mask for these addresses is 255.255.255.252. You assign one to each of the virtual TCP/IP interfaces on your partitions as shown in this figure.

In this example, TCP/IP traffic from partition A runs across the virtual Ethernet to the 10.1.1.74 interface on partition B. Because 10.1.1.74 is associated with the external proxy ARP interface 10.1.1.15, the packets continue out of the virtual Ethernet using the proxy ARP interface.

To configure a virtual Ethernet to use the proxy ARP connection method, complete these configuration tasks.

1. Step 1: Enabling logical partitions to participate in a virtual Ethernet
   The first step for associating the virtual interface with an external interface is to enable virtual Ethernet.
2. Step 2: Creating Ethernet line descriptions
   You need to perform this step in one of two ways depending on the model you are using. Select the appropriate procedure for your particular model.
3. Step 3: Turning on IP datagram forwarding
   Turn on IP datagram forwarding so that the packets can be forwarded among different subnets.
4. Step 4: Creating the interface to enable proxy ARP
   You need to create an external interface to enable proxy ARP.
5. Step 5: Creating the virtual TCP/IP interface on partition A
   You need to specify the virtual TCP/IP interface on Partition A.
6. Step 6: Creating the virtual TCP/IP interface on partition B
   You need to create the virtual TCP/IP interface on Partition B.
7. Step 7: Creating a preferred interface list
   You can now create a preferred interface list to control which adapters and IP addresses are the preferred interface for virtual Ethernet proxy Address Resolution Protocol (ARP) agent selection.
8. Step 8: Creating the route
   Creating the default route enables the packet to exit the virtual Ethernet network.
9. Step 9: Verifying network communications
   You can now verify your network communications.

 

Parent topic:

TCP/IP techniques connecting virtual Ethernet to external LANs

Related concepts
Network address translation method TCP/IP routing method Virtual Ethernet considerations