Tutorials - ADSL > Solwise SAR110 Router and No-NAT

Tutorials and FAQs: ADSL: Solwise SAR110 Router and No-NAT


This tutorial provides instructions for setting up the Solwise SAR110 ADSL Router for use in a "No-NAT" configuration involving a block of public IP Addresses.

An example of a block of 4 public IP Addresses:

1. 212.159.98.64 is the network address (Public IP address 1)
   
2. 212.159.98.65 is the router's IP address (Public IP address 2)
   
3. 212.159.98.66 is the IP address for your server (Public IP address 3)
   
4. 212.159.98.67 is the broadcast address (Public IP address 4)
   
   255.255.255.252 is the Subnet Mask

A typical network arrangement with this setup is illustrated in the diagram below. Note that Public IP Address 2 is applied to both the "LAN" and "WAN" sides of the router, and Public IP Address 3 is applied to the PC Server network interface which attaches to the Router. The PC Server, optionally, has a second network interface to which a series of workstations may be connected; all these interfaces use private IP addresses.


No-NAT Network Topology


Note: Most users will be assigned a single public IP address and should configure the router in its usual "NAT" mode. Use the procedure here only if you know you need to set the router for "No-NAT" operation.


Preliminaries

Before starting this work, make sure you have both the serial and Ethernet cables plugged in to your computer and the WAN cable is disconnected. Also, it is necessary to have the latest firmware which, at the time of writing, is VIK-1.38.030331e. Some earlier versions of firmware did not support true No-NAT operation.


Procedure

1. Configure the router's LAN IP address to the second address in the block provided by PlusNet. Also set the subnet mask. Once this has been done go to the Admin tab, select the commit & reboot link then click the commit button.
   
   
   LAN Configuration screen. [Click it for a larger image.]
   
   
   
2. On the Server PC, set the third IP address from your range as the PC/Server's IP address, and set the subnet mask as before. The default gateway should be set to the router's IP address.
   
   
   Windows PC TCP/IP Properties screen. [Click it for a larger image.]
   
   
   
   
3. At this point you need to connect to the router via telnet or RS232/hyperterminal. Then, at the command line, type the following command to delete the current ppp connection. (More information about connecting via the RS232 can be found in the supplied Solwise manual.)
   
   $delete ppp intf ifname ppp-0
   
   
   
4. Now enter the following command to create a new ppp connection, which borrows its IP address from the LAN/Ethernet port of the router:
   
   $create ppp intf ifname ppp-0 ppoa lowif aal5-0 numif eth-0 droute true
   
   $commit
   
   $reboot
   
   
   
5. Go back to the browser and access the router on the second IP address of the range eg http://212.159.98.65
   Set the ATM VC with the correct values VPI: 0, VCI: 38 and Mux type: VC.
   
   
   ATM VC Configuration screen. [Click it for a larger image.]
   
   
   
   
6. Now set your username and password in the ppp settings. (Click on the pencil icon under Action to bring up the data entry screen.)
   
   
   PPP Configuration screen. [Click it for a larger image.]
   
   
   
   
7. Then disable NAT in the services menu.
   
   
   NAT Options screen. [Click it for a larger image.]
   
   
   
   
8. When all this is complete, you can commit these changes then reboot the router.

This completes the process of configuring your block of IP addresses. Do not make any change using the quick config because this would completely undo all these changes that you have made!


Other Information

The PlusNet portal contains several pages of useful information about the Solwise SAR110 ADSL Router, including a Quick Start Setup Guide for the more usual NAT configuration. There are also procedures for Upgrading or Replacing the Firmware and for Connecting with a Console Cable, both of which may be useful to people wishing to carry out the procedure described in this tutorial.

Attention is also drawn to the page Quick Start Setup Guide No-NAT. It should be noted that the procedure outlined on that page is one which pertained prior to the firmware releases supporting true "No-NAT" operation, and enabled users of the router to make use of the extra public IP addresses available to them if they had opted for "No-NAT" from PlusNet, but it is not a full No-NAT configuration. In the technique given there, a "mapping" is made between the additional public IP Address and the internal (private) IP Address of one of the PCs on the LAN.


Acknowledgements

The Tutorials Team is indebted to Aaron Bolton of PlusNet Support for permission to use this article.

---

Original Article by: task - Edited by: acarr