ASUS TM-AC1900 Wireless-AC1900 Dual-Band Gigabit Router Expired

My suggestions to simplify the guides...

General Information:
Default T-mobile Router IP is 192.168.29.1
Default Username is admin
Default Password is password

Once you switch to ASUS CFE and firmware
Default ASUS Router IP is 192.168.1.1
Default Username is admin
Default Password is admin


#1 YOU DON'T NEED TELNET (if you let the router update itself to 3.0.0.4.376_3169 it includes SSH, so no need to downgrade firmware or play with html)

Web interface Administration -> System -> Enable SSH (then Apply)

Telnet is just an insecure version of ssh. Use ssh to log into the router.

How to use SSH with your Asus Router:

Log into your router's web interface as usual (web browser to 192.168.29.1 if you are on T-mobile firmware or 192.168.1.1 if you are on Asus firmware, both assuming you haven't changed the default IP).

Once in web interface click Administration on lower left and then the System tab toward the top. One option should be to enable SSH. Set that to yes or on and press Apply at the bottom.

Run putty.exe to open an ssh terminal. Get putty.exe here:
http://www.chiark.greenend.org.uk...nload.html

Run putty.exe, type the IP of your router, username admin, password is password, admin, or whatever you changed it to. You are now logged into the router and have terminal access without needing telnet. It may ask you about storing a host key, you can say yes or no, it doesn't matter.


#2 YOU DON'T NEED A USB STICK TO GET FILES ON OR OFF YOUR ROUTER
You can copy files back and forth to the router with a simple drag and drop interface with WinSCP, a windows GUI for the secure copy command, scp.

Download and run WinSCP from here:
https://winscp.net/eng/download.php

When you open WinSCP, it will have a setting at the top for File Protocol. Set this away from SFTP and switch it to SCP. Type your router's IP into the Host name box. It will ask username and password. It may ask you about storing a host key, you can say yes or no, it doesn't matter.

You now have drag and drop access to your router. It defaults to the /tmp/home/root, which is perfect for us.

#3 YOU DON'T NEED TO UNPLUG THE ROUTER
There is a power switch button on the back of the router. It's easy to use with one hand and saves you the hassle of unplugging and replugging the power adapter. The reset button, which requires a pen or some poking tool, is a little above this power button. To reboot router, press power button once to turn the router off, wait 10 seconds, then press it again to power it on.

#4 YOU DON'T NEED A HEX EDITOR
As is pointed out in Engineer's guide, there's a cfe.exe which copies the MAC addresses for you, and you can use his provided grep commands the verify the correctness. You don't need to use a hex editor to do this.

---------------------------------------------------------------------------------

I had used the router for a few days with T-mobile firmware and had allowed it to upgrade to 3.0.0.4.376_3169. Since I used SSH instead of telnet, allowing this T-mobile firmware update didn't end up being a bad thing or adding any hassle. In other words, don't worry about connecting the router to the internet or upgrading it when you get it if you want to try the T-mobile firmware.

Here are my shortened/simplified instructions from whatever T-mobile firmware you have (if you are on older firmware than 3.0.0.4.376_3169 that has Telnet, you can use that instead of SSH, but if you are on firmware that doesn't have SSH or Telnet, you can use the Web Interface to allow the router to update itself to 3.0.0.4.376_3169, which has SSH, before you continue).

1. Enable SSH in the Web interface
Administration -> System -> Enable SSH

2. Download and run Putty.exe and WinSCP.exe to log into your router from both programs.

3. Slightly modified version from Engineer's excellent guide:
https://slickdeals.net/forums/showpost.php?p=73690012&postcount=3895
- From Putty type:
cat /dev/mtd0 > original_cfe.bin
- From WinSCP click refresh on right side and see that original_cfe.bin has now appeared
- Make New Folder on your PC (left side of WinSCP) and drag original_cfe.bin from right side to left side (from router to the new empty folder on your PC)
- Download ASUS CFE 1.0.2.0:
https://mega.nz/#!IxZTAbDZ!Rardt8...tByYIvWYgY
- Unrar that file into the same New Folder as original_cfe.bin
(If you don't already have WinRAR, get that here: http://www.rarlab.com/download.htm)
-Rename that CFE file from rt-ac68u_1.0.2.0_us.bin to new_cfe.bin (right click, rename)
-Download cfe.exe and unrar into your New Folder on your PC.
https://mega.nz/#!9kZjGS6C!tTOddF...uCshw0qx-Q
-On your PC, use the normal windows explorer folder browser (not WinSCP) to navigate to your New Folder that contains these three files (original_cfe.bin, new_cfe.bin, and cfe.exe).
-Double click cfe.exe. Say yes you trust it to run.
-If it worked, a new_cfe.bin.bak file will appear. You don't need this file, but it shows cfe.exe did something.
-In WinSCP, drag new_cfe.bin in the left window (your New Folder) to the right window (your router).
**************************IMPORTANT CHECK*************************
-In Putty, check that cfe.exe worked and you copied things correctly by typing (copy here, right click in Putty to paste, then press Enter):
grep mac ./original_cfe.bin ./new_cfe.bin
(if the results don't match, STOP and recheck your work).
grep secret ./original_cfe.bin ./new_cfe.bin
(again, if the results don't match, STOP and recheck your work).
***************************************************************************

**********IMPORTANT (while you still have internet access)***********
-Download this ASUS firmware version 376.3626 and save it on your PC for later:
http://dlcdnet.asus.com/pub/ASUS/...763626.zip

It's important that you have that exact firmware version downloaded before you disconnect from the internet. It will expand your rootfs partition from 32MB to 64MB to allow for modern firmware. You can unzip it into your New Folder or an easy to find place like your desktop. The file is named FW_RT_AC68U_30043763626.trx after you unzip it.

----- Begin Optional/Educational ------

In Putty, you can check your current partition size using the command:
df -h

If you have a 32MB partition, jffs will also be around 32MB. If you have upgraded to 64MB, jffs will show something closer to 64MB.

Example of 32MB partition with T-mobile firmware:
admin@(none):/tmp/home/root# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 13.9M 13.9M 0 100% /
devtmpfs 124.8M 0 124.8M 0% /dev
tmpfs 124.9M 256.0K 124.6M 0% /tmp
/dev/mtdblock6 30.8M 1.1M 29.7M 3% /jffs
/dev/mtdblock7 1.3M 388.0K 892.0K 30% /T-Mobile

Example with 64MB partition after updating to Asus firmware (which we will do later):
admin@(none):/tmp/home/root# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 37.0M 37.0M 0 100% /
devtmpfs 124.8M 0 124.8M 0% /dev
tmpfs 124.9M 1.3M 123.6M 1% /tmp
/dev/mtdblock4 62.8M 1.7M 61.0M 3% /jffs


You can check your CFE version by typing:
nvram get bl_version

With the T-mobile firmware that I allowed to upgrade, the output looked like:
admin@(none):/tmp/home/root# nvram get bl_version
2.1.2.6

After I completed the switch to the ASUS CFE, the output looks like:
admin@(none):/tmp/home/root# nvram get bl_version
1.0.2.0


You can check your hardware revision by typing:
nvram get HW_ver

Mine is hardware revision 1.7 as shown by this output:
admin@(none):/# nvram get HW_ver
170

You can check your router's CPU and RAM speed by typing:
nvram get clkfreq

Mine is the default 800MHz CPU and 666MHz RAM as shown in this output:
admin@(none):/tmp/home/root# nvram get clkfreq
800,666

------- End Optional/Educational ------

-Download the CFE flashing utility:
https://mega.nz/#!RxhHxY6C!VYkscS...ZLpdb_SVSk
-Unrar mtd-write and use WinSCP to copy it onto your router (the right WinSCP window).
-In Putty, test if you have everything you need by typing:
ls -l (that's LS -L but in lower case)

Output should look like this showing the three files:
admin@(none):/tmp/home/root# ls -l
-rwxr--r-- 1 admin root 523364 Nov 4 2014 mtd-write
-rw-r--r-- 1 admin root 231923 Nov 27 14:32 new_cfe.bin
-rw-rw-rw- 1 admin root 524288 Nov 27 11:20 original_cfe.bin

-See if mtd-write will work by typing:
./mtd-write

Output should be:
admin@(none):/tmp/home/root# ./mtd-write
Usage: ./mtd-write -i file -d part

You will probably get permission denied like this:
admin@(none):/tmp/home/root# ./mtd-write
-sh: ./mtd-write: Permission denied

You just need to type this:
chmod u+x mtd-write (this will make the file executable)

If you get an error about not found like this:
admin@(none):/tmp/home/root# mtd-write
-sh: mtd-write: not found

You need to make sure the ./ is in front when you type ./mtd-write

So, if your output is like this, you are ready to use the command to update your CFE:
admin@(none):/tmp/home/root# ./mtd-write
Usage: ./mtd-write -i file -d part


-Actually write the ASUS CFE version and overwrite the T-mobile one by typing:
./mtd-write new_cfe.bin boot

-Reboot the router by typing:
reboot

WinSCP and Putty will lose connection. You can close WinSCP since you are done with that. You should also close putty because it will be unresponsive.

-After router is done booting (a minute or two) SSH into router and check CFE version by typing:
nvram get bl_version

If I remember correctly, it already displayed 1.0.2.0 at this point in the process.

-Reset NVRAM by the hardware method:
Power router off using power button on the back
Wait 10 seconds
Press and hold the WPS button
Power the router back on while continuing to hold the WPS button for 15-20 seconds

For me, at this point having uploaded and installed the ASUS CFE version 1.0.2.0 and reset the NVRAM, the router's IP switched by itself from 192.168.29.1 to 192.168.1.1. This was a bit of guess and check over several tries because the guides didn't work until I realized this. So, for me, the next set was to enter recovery mode as follows:

*** Enter Recovery Mode to install stock Asus firmware 376.3626 that you downloaded before ***
-Set PC's IP address to static 192.168.1.2 (not sure if this is needed, but oh well)
-Unplug all other ethernet cables except the one to your PC which is in yellow port 1 (again, not sure if this ended up mattering but I did it)
-Turn off router with power button
-In a browser (I can't remember it only worked with IE or also other browsers) type 192.168.1.1 and watch it spin to look for it
-Press and hold reset button with pen
-Power on router with power button
-Continue to hold reset button for 20-30 seconds
-If you win, a Mini-CFE web page will appear in your web browser (if you can't get into the Mini-CFE, try to ping 192.168.1.1 or 192.168.29.1 to see which one your router is using then keep trying
-Once it works, use the Mini-CFE web page to install FW_RT_AC68U_30043763626.trx

-After it installs and reboots itself, you are free to log into 192.168.1.1 with admin/admin and do whatever you want for other firmware. Your jffs should now be around 64MB (see above to check), so any firmware will work. I let the web interface update me to stock Asus 3.0.0.4.380_4118. I'll probably go Merlin soon.

Thanks to Engineer and others for the guides. I just thought I'd share/update with my experience to give others hope and motivation to try as well. The newer Asus firmware has several other new features over the newest T-mobile firmware and also works with the Asus Router app: https://www.asus.com/asus-router-app/

Good luck!

The AC1900 from T-Mobile is a rebranded Asus RT-AC68U (or RT-AC68R if buying from Best Buy). It has a custom firmware load that prioritizes WiFi calling, but that can be replaced with the standard firmware or other custom firmware.

FYI, it will show $5.99 for standard shipping when you add it to cart, but that goes away when you are on the final checkout page.

WOW awesome deal.

I have this router it is AMAZING!!!