Scenario: Connecting your office LAN to the Internet with a modem

Administrators typically set up office networks for employees to access the Internet. Administrators can use a modem to connect the system to an Internet service provider (ISP). LAN-attached PC clients can communicate with the Internet using the IBM® i operating system as a gateway.

Situation

The corporate application that your company uses requires your users to access the Internet. Because the application does not require large amounts of data to be exchanged, you need to be able to use a modem to connect both your system and LAN-attached PC clients to the Internet. The following figure describes an example of this situation.

Figure 1. Connecting your office LAN to the Internet with a modem
Connect your office LAN to the Internet with a modem

Solution

You can use your integrated (or other compatible) modem to connect your system to your ISP. You need to create a Point-to-Point Protocol (PPP) originator profile on the system to establish the PPP connection to the ISP.

After you make the connection between the system and the ISP, your LAN-attached PCs can communicate with the Internet using the system as a gateway. In the originator profile, you need to make sure that the Hide addresses option is on, so that LAN clients that have private IP addresses can communicate with the Internet.

If your ISP supports IPv6 addressing, you can also enable IPv6 in the originator profile.

Now that your system and network is attached to the Internet, you must understand your security risks. Work with your ISP to understand their security policies and take further actions to protect your system and network.

Depending on your Internet usage, bandwidth might become a concern.

Sample configuration

To set up a sample configuration from IBM Navigator for i, follow these steps:

  1. Configure an originator connection profile on your system.

    Ensure that you select the following information:

    • Protocol type: PPP
    • Connection type: Switched-line
    • Operating mode: Dial
    • Link configuration: This might be single line, or line pool, depending on your environment.
  2. On the General page of the New Point-to-Point Profile Properties, enter a name and description for the originator profile.
  3. Click Connection to open the Connection page. Choose the appropriate Line name or create a new one by typing a new name and clicking Open.
    1. On the General page of the new line properties, select an existing hardware resource. If you select an internal modem resource, then the modem type and framing type settings will be automatically selected.
    2. Click OK to return to New Point-to-Point Profile Properties page.
  4. Click Add, and type the telephone number to dial to reach the ISP server. Ensure that you include any required prefix.
  5. Click Authentication to open the Authentication page, select Allow the remote system to verify the identity of this system. Select the authentication protocol, and enter any required user name or password information.
  6. Click TCP/IP IPv4 Settings to open the TCP/IP IPv4 page.
    1. Select Enable IPv4.
    2. Select Assigned by remote system for both local and remote IP addresses.
    3. Select Add remote system as the default route.
    4. Check Hide addresses (full masquerading) so that your internal IP addresses are not routed on to the Internet.
  7. If you want to enable IPv6 addressing, click TCP/IP IPv6 Settings to open the TCP/IP IPv6 page.
    1. Select Enable IPv6.
    2. b. Select *None for Fixed local IP address.
    3. Select Generate for Interface identifier.
    4. Select No for Allow remote system to access other networks (IP forwarding).
    5. Select Accept a default route.
  8. Click DNS to open the Domain Name System (DNS) page, enter the IP address of the DNS server that is provided by the ISP.
  9. Click OK to complete the profile.
To use the connection profile to connect to the Internet, right-click the connection profile from IBM Navigator for i, and select Start. The connection is successful when the status changes to Active. Refresh to update the display.
Note: You must also ensure that the other systems in your network have proper routing defined, so that Internet bound TCP/IP traffic from these systems is sent through the system.