Enabling WDS Mode on the Motorola WR850G Router (5.13 Firmware):

On Networking/DHCP Server Page, disable the DHCP Server on the Router being used as a repeater. Set the second unit to a LAN Private IP Address of 192.168.10.2, subnet mask to 255.255.255.0. (Make sure you adjust the DHCP Range on the Master Router to NOT include the .2 range, I would suggest setting the DHCP starting range on the Master Router to start at 192.168.10.10)

On WIRELESS BASIC Page:

Set both SSID's to the same thing (Capitalization and spaces counts)
Set both to the same channel.
Set both Operations Modes to the same thing (Compatibility 802.11b/g)
Hit APPLY Button at bottom of page.

On WIRELESS SECURITY Page:

Enable SSID Broadcast
Set ESS Authentication to "Open System"
Set Encryption Status to "None"
Disable "Wireless MAC Address Control"
Hit APPLY Button at bottom of page.

On WIRELESS ADVANCED Page:

Make sure Short Preamble and Frame Bursting are disabled.
Enable WDS Mode (on 4.03 firmware do not check this box as WDS is already enabled)
Enable WDS Restrict Mode
Enter the other routers WIRELESS MAC address in the others WDS Restrict MAC Address Area (Both routers have to have the others Wireless MAC entered here)
Hit APPLY Button at bottom of page.

RESTART UNITS (Recommend restart main router first, let it fully boot then power-up the second unit)

REMEMBER: The second (repeater) unit MUST be in radio range of the Main Router for this to work. It is recommended that you station the repeater in an area that has at LEAST a LOW to FAIR signal on your client machines, do not place it in locations that have a VERY LOW or non-existent signal.)

Once you have this working you can then turn on security. ONLY WEP is currently supported in WDS Mode (WPA will be supported in the new firmware). When you enable security it must be identical on both units (ESS Authentication and Encryption Status need to be identical, as well as the WEP Key). If you decide to enable "Wireless MAC Access Control List" on the Wireless/Security page, you must enter the Wireless MAC of each router in here as well as the Wireless MAC of any clients (in both routers).

The above information provided by WirelessGuy0 in this thread: Enabling WDS Mode on the Motorola WR850G

*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Motorola or any of its affiliates.

One of the common causes for this is, having multiple machines in your home, and trying to access the router's page from each machine. Yes, it is possible to get to the router's access page, but during that period of time, no other system can login to the router.

So, how is this resolved? Quite simple, really. Just go to the machine that previously had the configuration page open, and there should be an option to log out on the left-hand side, click it:

*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Motorola or any of its affiliates.

You can do this by pointing your browser's address to: »192.168.10.1 - you will be prompt for user name and password. The user name and password should have been setup once you linked your router to the network, as part of the CD setup protocol. The CD should be labeled: Motorola Installation Wizard - Wireless Broadband Router WR850G (or WR850GP).

It is very important to keep the CD in a safe place, just in case you're unable to access the router, for any reason.

*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Motorola or any of its affiliates.

WARNING: BEFORE YOU GO ANY FURTHER. FLASHING YOUR ROUTER WITH 3rd PARTY FIRMWARE MIGHT DAMAGE YOUR ROUTER, AND IT WOULD TAKE LOTS OF TWEAKING TO BRING IT BACK TO LIFE AT BEST. ALSO YOUR WARRANTY WILL BE WAIVED. FLASH AT YOUR OWN RISK.

With all the problems the WRT850G presents, some users might want to look for other options like OpenWrt firmware, based on Linux. So far users using OpenWrt firmware (fw) report superior performance and stability results. During this process make sure you use the LAN ports of the router and NOT the wireless.

Why you should NOT get involved with 3rd party fw:

if youre not familiar or at ease with using command lines
if you need a GUI(web interface) to do your configurations
if youre not willing to do some research on how to use OpenWrt
OpenWrt has a steep learning curve
WEP its easy to get going, WPA takes some work.
Last but not least if you plain and simple dont know what you doing
If any of the above apply to you, pray for the next Moto Fw miracle

So lets do it. Have some chill pills ready, a bottle of patience and few shots of courage.

1. Downgrade your Motorola fw to version 4.03 using the GUI interface.
2. Reboot the router.
3. Download the OpenWrt fw from their site. Currently the latest ver. is 20050202
4. Extract the files. Youll need the openwrt-linux.trx file. There is a folder called Packages which contains many goodies for your router, after you flash it
5. Then use the Moto fw bug and point your browser to:

»192.168.10.1/frame_debug.asp

6. Enter the following commands one at the time.

nvram set boot_wait=on
nvram commit

7. Reboot the router.
8. Now youll have to tftp your new fw into the device. You can use whatever TFTP clients you want. In XP you can use the following command, make sure youre in the folder where you previously extracted the files from the command prompt:

tftp -i 192.168.10.1 put openwrt-linux.trx
(you might need a few tries if you dont time it right)

9. After you flash, the router will automatically reboot and run the firstboot sequence which basically sets up your partitions and so on.

DO NOT REBOOT THE ROUTER DURING THIS TIME UNLESS YOU LOOK FOR TROUBLE

10. Wait until you can telnet into the LAN. The address should be 192.168.1.1 but in many cases some or all of the old configuration parameters from the Moto Fw might carry over. In which case obviously youll telnet into 192.168.10.1
11. You can reset your nvram with the following command:

mtd erase nvram
reboot

12. On OpenWrt documents and forum, youll find lots of help

ENJOY YOUR TRULY FUNCTIONUAL WIRELESS ROUTER

The router has a bridge between the LAN and the Wireless, so first you might want, for many reasons to break this bridge.

nvram set lan_ifname=vlan0
nvram unset lan_ifnames

Like this you have the LAN defined as vlan0, and obviously you can set your LAN as static or DHCP.

nvram set lan_proto=static
nvram set lan_ipaddr=192.168.10.1
nvram set lan_netmask=255.255.255.0

On WRT850G the wireless corresponds with eth1, so:

nvram set wifi_proto=static
nvram set wifi_ipaddr=192.168.11.1
nvram set wifi_netmask=255.255.255.0

Get the idea with braking the bridge now? Ok. Now lets make this baby an AP and define the SSID:

nvram set wl0_mode=ap
nvram set wl0_ssid=ourgreatrouter

Enable WEP:

nvram set wl0_wep=on
nvram set wl0_key1=1234567890 ----whatever you want of course

On the WAN side of things you can go like the LAN, DHCP or static. I use static because of my network layout.

nvram set wan_proto=static
nvram set wan_ipaddr=192.168.1.1
nvram set wan_netmask=255.255.255.0

The default gateway: nvram set wan_gateway=192.168.1.2
And the WAN DNS: nvram set wan_dns=192.168.5.1 9 (as ex.)

Now just do nvram commit and reboot.
You should install dropbear (client/server SSH)
ipkg update
ipkg install dropbear

Reboot and make sure you can logon using SSH. AFTER that you could remove the Telnet portion altogether: rm /etc/init.d/S50telnet
So form now on, youll be able to do many things, and after all the frustration with the original fw, and after all this work, you have a fully functional router.
I tried to help you here, so you get a head start, so now youre on your own.

We all should thank the great people participating in the OpenWrt community for making this possible.

*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Motorola or any of its affiliates.

How do I set up Port Forwarding for the Motorola WR850G Wireless Router?

Link provided by WirelessGuy0

*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Motorola or any of its affiliates.

Similar in appearance and features, the SB5101 & SB5120 are not repackaged versions of the SB5100.

The SB5100 uses the Broadcom chipset/processor BCM3348.

The SB5101 uses the Broadcom chipset/processor BCM3349.

The SB5120 uses the Texas Instrument chipset/processor TI4401.

Each modem has its own firmware versions unique to its model. All other product specifications are the same for all 3 models.

The SB5100 has been discontinue. 

The SB5101 is a current model. 

The SB5120 has been discontinued.

*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Motorola or any of its affiliates.

How do I start Port Triggering for the Motorola WR850G Wireless Router?

Link provided by WirelessGuy0

*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Motorola or any of its affiliates.