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.
INTRODUCTION:
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.
REFERENCES:
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/Ameritech’s 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”!
ASSUMPTIONS:
1. The local address of the 3Com 812 is 192.168.254.254
2. The static IP address range which SBC/Ameritech has assigned you is 169.129.154.225 – 169.129.154.229
3. The local IP addresses to be associated with the public static IP addresses are in the range 192.168.254.205 – 192.168.254.209. Note that any 5 local addresses that don’t 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
169.129.154.225 -> 192.168.254.205
169.129.154.226 -> 192.168.254.206
169.129.154.227 -> 192.168.254.207
169.129.154.228 -> 192.168.254.208
169.129.154.229 -> 192.168.254.209
Router public address: 169.129.154.230
Router private address: 192.168.254.254
PROCEDURE:
1. Start up Internet Explorer and enter the router’s address (192.168.254.254) instead of a URL. You should be prompted for a user name and password – enter the router’s 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: 169.129.154.225
Private IP Address: 192.168.254.205
10. Repeat steps 8 and 9 for the remaining four pairings:
Public IP Address: 169.129.154.226
Private IP Address: 192.168.254.206
Public IP Address: 169.129.154.227
Private IP Address: 192.168.254.207
Public IP Address: 169.129.154.228
Private IP Address: 192.168.254.208
Public IP Address: 169.129.154.229
Private IP Address: 192.168.254.209
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.
HINTS FOR USING THE NEW CONFIGURATION:
PC’s that are to be hidden from direct access from the Internet will continue to use the router’s address translation. They should be set up with a default gateway of 192.168.254.254 (mask 255.255.255.0) and traffic from them will appear to the outside world to have originated from the router’s public address of 169.129.154.230. If you wish to use the router as a DNS forwarder (assuming that it is configured to do so) enter the router’s address (192.168.254.254) in the PC’s 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 169.129.154.228 you would configure the server with the following settings:
IP Address: 192.168.254.208
Mask: 255.255.255.0
Gateway: 192.168.254.254
DNS: 192.168.254.254
*** 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 
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by RadioDoc edited by lev
last modified: 2005-06-28 13:44:21 |
