DD-WRT:Repeater

Introduction
If you got here from Google you may wish to read Linking Routers first.

This is by far the EASIEST and ONLY working solution found so far after testing on multiple units. Works with stock firmware from Buffalo and WRT on any Linksys V2.4 (with V1.1 it works also)
 * No setup changes are required to be made to your host-router / AP although some revisions or adjustments may be desirable, as stated below.
 * if your host AP is 192.168.1.x, then your repeater could be subnet 192.168.2.x or 192.168.69.1 or ... any other unique subnet in your network. If you need a repeater-type solution in the same subnet you are in the wrong place. You need to read Linking Routers first..!

Preparation
You need to know the host router's access credentials:
 * SSID
 * the security settings
 * its IP address
 * prepare and verify the DD-WRT to be configured as a repeater
 * Note: In order for this work, you should use any V24 build except V24-RC6.2. There were problems with that build!
 * cable-connect your repeater-to-be to a laptop or desktop
 * install or upgrade the DD-WRT firmware (if required)
 * do a 30 sec reset (see Hard reset or 30/30/30).
 * verify which chip set your device uses and read Broadcom / Artheros considerations, below
 * proceed with installation

Broadcom Considerations
Note: In order for this work, you should use either build 12548 or 12874. NEVER use v24 SP1

Atheros Considerations
There is no "Repeater" mode on Atheros units, but you still can use it as repeater, just set the original interface as "client" and get it to connect to your AP, then create a virtual interface to broadcast the new SSID.

Repeater Setup
To set it up as repeater do the following:
 * 1) Do a 30 sec reset (see Hard reset or 30/30/30).
 * 2) Under Wireless -> Basic Settings:
 * 3) *Wireless mode: Repeater
 * 4) *Wireless Network mode: (set to match the host)
 * 5) *Wireless Network Name (SSID): the SSID of the network you connect to
 * 6) *Save
 * 7) *Add 1 virtual interface
 * 8) *Enter a new (unique) SSID of your choice
 * 9) *Save
 * 10) Under Wireless -> Wireless Security:
 * 11) *Physical Interface wl0:
 * 12) **Enter the necessary settings to connect to the wlan you'd like to repeat (if no security, leave disabled...but consider enabling security for both host AP and Repeater)
 * 13) **Save
 * 14) * Virtual Interface wl0.1:
 * 15) **Choose the best security mode, which should be WPA2-AES whenever possible.
 * 16) **Enter a security key
 * 17) ***Note: When using security on both the physical and virtual interfaces, you MUST usually use the same security type, and exactly the same passphrase on both the physical and virtual ssid. If you cannot connect when trying different security or passphrases, make them identical.
 * 18) **Save
 * 19) *Note: If you experience problems when setting up for the first time, a leading practice is to configure without any encryption (i.e. setting security to "None") at first, until the unit is confirmed to be working properly, and configuring encryption as a later step.
 * 20) Under Setup -> Basic Setup:
 * 21) *Network Setup:
 * 22) **Here you define the repeater's own subnet
 * 23) **Set IP address to a different subnet from the Host AP you wish to repeat
 * 24) ** Example: if host AP is 192.168.1.x, assign repeater to 192.168.2.1
 * 25) **Set up your DHCP range if you desire
 * 26) *Save
 * 27) Under Security:
 * 28) *Uncheck all items in the "Block WAN Request" section (except Filter Multicast)....THEN disable the SPI firewall
 * 29) **Note: If you are very concerned about security, a Repeater might still work okay with the SPI firewall enabled. If you decide to leave it enabled but experience problems, keep this step in mind.
 * 30) *Save
 * 31) Under Administration:
 * 32) *Enter all other necessary information, change GUI password,...
 * 33) *Click the Apply Settings button

Testing


 * After the Repeater has rebooted, disconnect power and let it cool a bit... (let ARP expire)
 * Turn power back on and let it boot
 * See if you can ping 192.168.1.x and access an outside web site, say Google or Yahoo

Footnotes

When the unit has logged onto the Host WLAN and has begun repeating its signal, you will see the DHCP address (generally in the 192.168.1.100-150 range) in the upper right-hand corner as the WAN address. As long as you see quad zeros up there (0.0.0.0), you are not linked and are not repeating. You might click the "reload) button on your browser once or twice to make sure the WAN IP is fresh while you are making changes. Make sure your repeater is within radio range of your host network; the WRT54GL has a great radio in it, and if you want heat, you can go to Wireless/Advanced Settings and jack Xmit Power up as high as 100 and the transmit PA will still run linear enough to support 54 Mbpsec OFDM. Once you are up and running (repeating), you can get to the repeater's web GUI from your local intranet by entering its private IP address in your web browser.

But for the pièce de résistance, go into the Host WLAN router's web GUI (NAT/QoS/Port Forwarding on DD-WRT.v24 beta) and set up a port forward so you can check on and fully access and control your new repeater from Outside, i.e. via the Internet. Look up the address that DHCP has assigned to your new repeater (the name you entered in Setup/Basic Setup/Optional Settings/Host Name will appear in the DHCP clients table of the Host router under Status/Sys-Info), and write it down. Then go to Port Forwarding and click "Add." Make the forwarded port (Port from) something you can remember easily, like 8128 if you found your repeater on 192.168.1.128, for example. Click Both for Protocol, enter the IP private IP address of your repeater in the IP Address box, enter Port 80 (http default) in the "Port to" box. Or if you want to be tricky, enter something besides 80, but just be sure this matches the active Web GUI port number on your repeater). Lastly, be sure to check "Enable," and then click "Save Settings" (v23) or "Apply" (v24 beta). Then go Outside, and take a look at your main WLAN router at its public IP address (or DDNS link), and then take a peek at your repeater's Web GUI on the same address (or DDNS link) followed by :8128, e.g. http://yourwlan.dyndns.org/ for your Host router and http://yourwlan.dyndns.org:8128/ for the repeater. But you knew that already.

Voilà!

Tips/Gotcha's/Problems

 * If you use Static Leases to control your Repeater's IP addresses...please note that with the new RC6 builds the WLAN MAC address is now duplicated to the WAN MAC address. This will require you to change the MAC address value in the Static Lease section on the Host AP (if you use this mode for your managed network)....RC5 and earlier used MAC+1 for Wireless...with RC6+ it will now be MAC+2.


 * I have seen on some networks where Repeater mode will not provide a reliable connection if the STP function is Enabled on the Basic Setup page...Set it to Disabled and see if your connection improves.


 * I had a problem with Post RC7-9068 builds where if you would manually disconnect from the Virtual SSID and try to reconnect, it would not. Power cycling the router was the only work around. Make sure that the "Use DNSmasq for DHCP", "Use DNSmasq for DNS", and "DHCP Authoritative" are all check marked on the Setup>>Basic Setup page to correct this.


 * You need to be on a different subnet then the host AP you are connecting to (Physical network)...try setting it to something like 192.168.69.1 on the Setup>>Basic Setup tab (if a physical of 192.168.1.1 is used for the host AP) - 09/17/07


 * If the host AP settings Wireless>>Basic Settings>>Wireless Network Mode is set to "G-only" then your repeater must also be set the same way....otherwise you will not make the connection from the repeater side - 09/22/07


 * Tests have shown that there is no way to lock a Repeater onto a particular channel - 2/12/2009


 * I was not able to get online with the Gateway and the Local DNS containing my router's IP as Stuckeymax suggested. Instead I left them as 0.0.0.0 and all was good.


 * Also take note of the fact that all repeaters, including this Wlan Repeater mode, will sacrifice half of the bandwidth available from the primary router for clients wirelessly connected to the repeater. This is a result of the repeater taking turns talking to not just one partner, but to two, and having to relay the traffic between them. As long as your bandwidth requirements are within this halved bandwidth amount there will be little or no reduction in "speed".


 * I tried a daisy chain of 4 routers AP-Rpt-Rpt-Clt, G-Only WPA2, all DHCP client from the previous, all managing it's own subnet with it's own DHCP-DNSMasq Authoritative (192.168.[1-2-3-4].0/24. Worked fine even with SPI firewall defaults enabled. No issues to manage all nodes from the net with the help of Port Forwardings and Port Range Forwardings. Wrt54GL1.1 dd-wrt v24 post sp1 build10776


 * I tried getting this working on the WNDR330 with build 13064 with no success. I could connect when security was turned off but not with it. I then downloaded the 13491M build from here [] and after following the steps listed above, including 2 hard reboots everything was fine.