Scenario: Share a modem between logical partitions using L2TP

You have virtual Ethernet set up across four logical partitions. Use this scenario to enable selected logical partitions to share a modem. These logical partitions will use the shared modem to access an external LAN.

Situation

You are the system administrator at a medium sized company. It's time to update your computer equipment, but you'd like to do more than that; you want to streamline your hardware. You start the process by consolidating the work of three old servers onto one new iSeries™ server. You create three logical partitions on the iSeries server. The new iSeries server came with a 2793 internal modem. This is the only input/output processor (IOP) you have that supports PPP. You also have an old 7852–400 electronic customer support (ECS) modem.

Solution

Multiple systems and partitions can share the same modems for dial-up connections, eliminating the need for each system or partition to have its own modem. This is possible by using L2TP tunnels and configuring L2TP profiles which allow outgoing calls. In your network, the tunnels will run over a virtual Ethernet network and a physical network. The physical line connects to another server in your network, which will also share modems.

Details

The following figure illustrates the network characteristics for this scenario:

Figure 1. Multiple systems sharing the same modem for dial-up connections
Network diagram depicting multiple systems sharing the same modem for dial-up connections.

Network diagram depicting multiple systems sharing the same modem for dial-up connections.

Prerequisites and assumptions

Setup requirements for iSeries-A include:

i5/OS™ Version 5 Release 3 or later, installed on the partition that owns the ASYNC capable modems
Hardware that allows you to partition.
iSeries Access for Windows^® and iSeries Navigator (Configuration and Service component of iSeries Navigator), Version 5 Release 3 or later
You have created at least two logical partitions (LPAR) on the server. The partition that owns the modem must have i5/OS Version 5 Release 3 or later installed. The other partitions can have OS/400^® V5R2, V5R3, Linux^®, or AIX^® installed. In this scenario, the partitions are either using i5/OS or Linux operating systems.
You have virtual Ethernet created to communicate across partitions. See the following scenario: Create a virtual Ethernet network for interpartition communication.

Setup requirements for iSeries-B include:

iSeries Access for Windows and iSeries Navigator (Configuration and Service component of iSeries Navigator), Version 5 Release 2 or later