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A few days ago a lightning storm took out my Efficient Networks 5861 router. The only replacement that I had immediately available was a 3Com Officeconnect Remote 812 ADSL router. After some trial and error I was able to get the 3Com working with my SBC/Ameritech service. I have documented the procedure and present it here in the hope that it will be of assistance to others. What follows is a basic setup that will get the 3Com 812 working in a manner similar to the standard Efficient 5861 install.


This is a step-by-step procedure to configure a 3Com Officeconnect Remote 812 ADSL router to route static IP addresses provided by SBC/Ameritech to private addresses within your network. To do this you must have an SBC/Ameritech package that provides a block of five user-accessible static IP addresses.


1. If you do not yet have your 3Com 812 set up with a basic configuration, I have provided a step-by-step procedure for that process as a separate post.

2. An excellent description of the technical underpinnings of SBC/Ameritechs static IP offering was posted previously by dslknowitall as part of the thread How do I configure my 5861 when I get my static IP. Thank you dslknowitall!


1. The local address of the 3Com 812 is

2. The static IP address range which SBC/Ameritech has assigned you is

3. The local IP addresses to be associated with the public static IP addresses are in the range Note that any 5 local addresses that dont conflict with other devices on the local network may be used and the local addresses do not need to be contiguous.

Using these assumptions will result in a configuration with the following mappings:
     PUBLIC ADDRESS  -> PRIVATE ADDRESS -> -> -> -> ->

Router public address:
Router private address:


1. Start up Internet Explorer and enter the routers address ( instead of a URL. You should be prompted for a user name and password enter the routers administrative name and password.

2. Click on Configuration in the navigation bar at the left of the screen.

3. Click on the Remote Site Profiles button.

4. Highlight the remote site profile name corresponding to your SBC/Ameritech connection, and then click on the Modify button.

5. Click on the Next button to get to the second page of configuration items for the Remote Site.

6. Turn on the check marks next to both PAT and NAT, then click on the Modify button. This puts you in what 3Com refers to as SuperNAT mode.

7. Click on the Static button.

8. Click on the Add button.

9. A screen prompting for a Public IP address and a Private IP address will appear. Enter the first pairing and then click on the Add button:

Public IP Address:
Private IP Address:

10. Repeat steps 8 and 9 for the remaining four pairings:

Public IP Address:
Private IP Address:

Public IP Address:
Private IP Address:

Public IP Address:
Private IP Address:

Public IP Address:
Private IP Address:

These changes will not take effect until the connection to SBC/Ameritech is restarted. The next six steps will disconnect and then reconnect:

11. You should be at the Nat Static screen. Click on Prev to return to the Remote Site IP screen.

12. Click on Prev to return to the Remote Site Modify screen.

13. Turn off the check mark next to Enable Remote Site.

14. Click on the Modify button. The connection to SBC/Ameritech will be dropped.

15. Turn back on the check mark next to Enable Remote Site.

16. Click on the Modify button. The connection to SBC/Ameritech will be re-established.

The 3Com 812 should now be configured for routing of the five static IP addresses. Check everything for proper operation. If all is well, save the changes permanently using the procedure which follows. Prior to making the changes permanent you can revert to the previous configuration by power cycling the router.

17. If needed, re-establish a connection to the router using your web browser.

18. Select Tools from the navigation bar on the left side of the screen.

19. Click on Save Configuration.

20. When the Save Configuration screen appears, click on the Save Configuration button in the middle of the screen.

21. The progress of the save will be displayed. When it reaches 100% you are done.


PCs that are to be hidden from direct access from the Internet will continue to use the routers address translation. They should be set up with a default gateway of (mask and traffic from them will appear to the outside world to have originated from the routers public address of If you wish to use the router as a DNS forwarder (assuming that it is configured to do so) enter the routers address ( in the PCs DNS entry.

Servers or other devices that are to be visible to the public at one of the five assigned static IP addresses should be set up with one of the five translated private addresses. For example, using the assumptions above, to set up a server which will be seen by the public at you would configure the server with the following settings:
	IP Address:

*** WARNING *** Servers or other devices assigned to one of the five static IP addresses are wide open to access from the Internet. Be sure you have adequate safeguards in place to prevent malicious or inappropriate access to these machines!

Good luck and may your latencies be nominal!

Submitted by John Taylor

Feedback received on this FAQ entry:
  • i am trying to connet get the internet with but it will not conn

    2008-11-23 20:44:36

Expand got feedback?

by RadioDoc See Profile edited by lev See Profile
last modified: 2005-06-28 13:44:21