Universal Wireless Repeater Setup Guide

Introduction

A repeater functions as a regular client device that can simultaneously act as an access point, independent of the SSID and encryption type. It is crucial to understand that these are NOT the standard instructions for creating a Repeater or Repeater Bridge, which is the typical method for linking routers. These instructions are for an older, special UNIVERSAL repeater configuration and are considered out of date for linking routers you own. For instructions on connecting your own routers, please refer to the wiki on linking routers.

This guide provides step-by-step instructions for setting up a Universal Wireless Repeater appliance. This device can be placed anywhere and will wirelessly repeat the strongest available signal onto another wireless network, whether it is secured or open. This functionality is also known as Wireless Client Bridge or Range Extender. Unlike WDS, once this appliance is set up, it is compatible with any open network.

Architecturally, the repeater connects to another wireless router as a client, obtaining a single IP address via DHCP. The SSID network it connects to effectively becomes your ISP. Consequently, you (the client) will operate within your own IP address space, distinct from the address space used by the repeater.

Example: Imagine a neighborhood with three open wireless networks: "jojo", "linksys", and "internetmad". The repeater automatically receives an IP address from "jojo". If "jojo" uses the 192.168.1.0/24 network and your DD-WRT router receives 192.168.1.139, the repeater is configured to use the 172.16.100.0/24 network. When your laptop connects to the SSID named "repeater", it receives an IP address like 172.16.101.100 via DHCP. From your laptop's perspective, you are communicating with the "repeater". From the repeater's perspective, its gateway is "jojo", which likely has its own gateway via a cable modem or DSL.

Prerequisites

• Proficiency in using and accessing the Web Interface of your router.
• Familiarity with flashing your device's firmware.

These instructions can be followed quickly if you have prior experience.

Instructions

1. Install the latest DD-WRT v24 release candidate. Note that RC6.2 and earlier versions (like v23) do not support repeater modes.

   • Visit the UWR forum for test results on firmware versions.
   • Keep an Ethernet cable connected throughout these instructions to maintain connectivity across potential wireless network changes.

   NOTE: For WRT54GS v4 and WRT54GL devices, you must first flash the MINI GENERIC bin. Failing to do so may brick the router, requiring recovery via TFTP with the Linksys bin. When using Windows, it is recommended to use Internet Explorer, as Firefox 2.0.0.4 may not handle the new DD-WRT v24beta interface correctly.

2. Navigate to the "Setup" tab, then the "Basic Setup" sub-tab.

   • Change the "local IP address" to a unique subnet that differs from the device you wish to repeat (e.g., 192.168.69.1).
   • Save settings. For V24 versions released after 07/04/07, use the "APPLY" button.

3. Point your browser to the new IP address you selected in the previous step. Go to the "Security" tab, then the "Firewall" sub-tab.

   • Uncheck all firewall checkboxes and set the firewall option to "disable".
   • Save settings. For V24 versions released after 07/04/07, use the "APPLY" button.

4. Navigate to the "Wireless" tab, then the "Basic Settings" sub-tab.

   • Set "Wireless Mode" to "Repeater".
   • Under "Wireless Physical Interface", set the "Wireless Network Name (SSID)" to the network you wish to repeat. Set "Network Configuration" to "Bridged".
   • Click "Save Settings". The "Virtual Interfaces" section will appear only after saving these changes.
   • Click "Add" under "Virtual Interfaces". Enter an SSID (e.g., "repeater"). Ensure "AP Isolation" is set to "disabled" and "Network Configuration" is set to "Bridged".
   • Optional: Set the "Wireless Channel" to "Auto" or your preferred channel.
   • Click "Save Settings". For V24 versions released after 07/04/07, use the "APPLY" button.

   [EDIT-Redhawk] If the host AP's "Wireless Network Mode" (under Wireless>>Basic Settings) is set to "G-only", your repeater must also be set to "G-only" to establish a connection from the repeater side. (Date: 09/22/07)

5. To enable dynamic repeating of any network (making this a universal wireless repeater), configure the following to make the repeater connect to the first available SSID:

   • Go to the "Administration" tab, then the "Command" sub-tab.
   • Copy and paste the following command into the edit box:

   nvram set wl_ssid=""

   • Click the "Save Startup" button.

   Note: This method will not automatically repeat secure or encrypted networks. If your source network uses WEP or WPA, enter the SSID under the Physical Interface in step 4 instead, and proceed to the next step.

6. You can configure security (WEP, WPA, etc.) in repeater mode. An example application is to make the repeated network private for your exclusive use.

   • Go to the "Wireless" tab, then the "Wireless Security" sub-tab.
   • Setup WEP (or other security) under the virtual interface.
   • Configure your client/computer to use the same security settings.

   Note: You may also configure security for the physical interface (source) network if you intend to repeat a secure network. In the example provided, this is disabled. Enabling this may prevent the dynamic repeating functionality from working, as it hard-codes the source network.

7. The first time you connect to the repeater wirelessly, or after a disconnection, you might need to perform a "repair wireless network connection". For example, in Windows XP, right-click the wireless icon and select "Repair".

Optimizations

For dynamically repeating the STRONGEST signal (a more sophisticated approach than step #5), please read the AutoAP Wiki Article.

AutoAP is a script designed to continuously scan for open Wi-Fi connections, test their validity, and connect to the strongest signal. If a connection is lost, the script rescans to find the strongest valid signal again, maintaining a continuous internet connection in mobile or portable environments. The script's parameters are highly configurable, including options to configure secure connections.

For optional repeater performance enhancements:

• Go to the "Wireless" tab, then the "Advanced Settings" sub-tab.
• Set "Preamble" to "Short".
• Set "Xmit Power" to a value higher than the default (e.g., 200).
• Click "Save Settings". For V24 versions released after 07/04/07, use the "APPLY" button.

It is important to note that all repeaters, including this Universal Wireless Repeater mode, will effectively halve the available bandwidth from the primary router for clients connected wirelessly to the repeater. This occurs because the repeater must communicate with both the primary router and the client devices, relaying traffic between them. As long as your bandwidth needs are within this reduced capacity, you should experience little to no noticeable reduction in speed.

Troubleshooting

• Repeater modes may be broken in v24 RC6. Consider using an alternative version, such as RC5 or RC7+.
• If you encounter issues enabling repeater mode, first attempt to set up Client Mode or Client-Bridged Mode as a test. Once client mode is functioning correctly, switch to repeater mode (while retaining all other settings) to verify it still works, and then add the virtual interface(s).
• The first time you connect to the repeater wirelessly, or after a disconnection, you might need to perform a "repair wireless network connection". For example, in Windows XP, right-click the wireless icon and select "Repair".
• If your router has two antennas and you are experiencing high packet loss, removing the second antenna might help.
• Visit the UWR forum for the latest information on features and issues.
• There is a discussion on the Repeater Bridge page regarding wireless security shortcomings, which may also apply to the Universal Wireless Repeater.
• Some notes and downloadable files are available on Both Repeaters that could aid in troubleshooting.
• For WRT54G v5, select "assign wan port" to switch apply settings, then perform a hard reboot by unplugging and replugging the power.
• Setting ACK Timing to 0 on a Buffalo WHR HP G54 with DD-WRT v24 (05/24/08) std (SVN revision 9526) has been reported to disable network sharing between WinXP computers.

Links

Your testing results and enhancements are appreciated.

• For contributions to UWR: http://www.dd-wrt.com/phpBB2/viewtopic.php?p=42375
• For contributions to AutoAP: http://www.dd-wrt.com/phpBB2/viewtopic.php?t=6575