[michaelS]

I have been reading in this forum that client bridge mode is not supported by the Ralink SOC, but only the repeater bridge mode is supported.

That seems mostly fine, except for the possible loss of some wifi bandwidth.

Given that, is it possible to achieve a similar effect by configuring as a repeater bridge, then bringing down the ra0 interface:

[ch1291]

Thanks for your tip. I have an Edimax BR6574n (Ralink RT2880F) and want a client bridge too. The Edimax factory firmware is supposed to support it (hence my purchase), so I do think client bridge is supported on Ralink chips. Also, these guys https://www.flashrouters.com/blog/2011/07/21/featured-dd-wrt-vpn-router-review-of-the-day-airlink101-670w think so too.
Unfortunately, I couldn't get it to work, so am trying DD-WRT, but as you found out "Client Bridge" is simply missing from the drop down list of modes, which lead me to your post.
Being in mainland europe, I didn't bother with the country/region code fix and simplified your startup command to "ifconfig ra0 down". This seems to work fine on DD-WRT (R17201) as you found out. BTW: I ignored the vitual interfaces setup in the repeater bridge instructions, why bother? Anyway, DD-WRT brings up an AP with the same SSID as your primary AP, whether you like it or not - no choice. The virtual interface is yet another AP, as you will see with any WiFi scanner.

I now have some performance test results. I'm using 802.11n (only, not mixed), 2.4GHz, dual channel (40MHz/300Mb)), WPA2/AES. My primary router and AP is a Linksys E3200 running the factory firmware. I have ~9" of reinforced concrete floor between the E3200 and the BR6574n (which is why I want a wireless bridge - no cable route practical). I used iperf between a notebook wired to the E3200 and a desktop wired to my new WLAN bridge. I achieved speeds of 22-31Mb, depending on the bridge's antenna orientation and location in the room.
Previously, I had a Powerline setup and only got ~15Mb. Since my ISP (cable) is a reliable 25Mb I wanted more speed in my home LAN, also for my NAS. I have also tried the Linksys WET610N ethernet bridge (my first attempt), but I could only get ~17Mb out of it anywhere, very disappointing - I later figured out the antennae gain (only 1dBi) is probably to blame. So I'm now a fan of external antennae with 3dBi minimum gain!
As a comparison, my notebook (also dual channel) achieved ~37Mb in the same location, so I'm happy enough.
I hope that helps you.

[ramitbhalla]

Perfect that worked great for me on RT-N13U using DD-WRT Firmware: DD-WRT v24-sp2 (04/15/13) std - build 21286 (the MOST stable build I've found so far).

I'm able to use the Repeater Bridge (used the standard DD-WRT instructions to set it up) as a Client Bridge and don't have the second SSID signal.
Since the perl command did not work, I simply used