[img]http://cdn.techknowl.com/wp-content/uploads/2010/12/Redsn0w-0.9.7b1-jailbreak-259x300.jpg[/img]
As promised, iPhone Dev team announced Redsn0w 0.9.7b1 untethered jailbreak for iOS 4.2.1. Redsn0w 0.9.7b1 jailbreak is designed to work with iPhone 4, iPod Touch 4G and Apple iPad. Those who are using iPhone 3G, iPhone 3G S, iPod Touch 2G on iOS 4.2.1 already have a fully working untethered jailbreak with Redsn0w 0.9.6b6. As you might know, an untethered jailbreak let you restart your device to jailbreak mode, without the need of connecting the device to a computer. Redsn0w 0.9. 7b1 download released today is intended for Mac users who are interested in helping the dev team in testing the jailbreak for any bugs.

These are the requirements for running Redsn0w 0.9.7b1.

An Apple iPhone 4, iPod Touch 4G or iPad with iOS 4.2.1 installed.

iOS 4.2.1 ipsw (direct link here).

A developer account with Apple for getting iOS 4.2.1 beta 3.

You need your Signature Hash files saved (on Cydia server) for iOS 4.2.1 beta 3.

Mac OS X.

Steps for iOS 4.2.1 untethered jailbreak with Redsn0w 0.9.7b1.
[img]http://cdn.techknowl.com/wp-content/uploads/2010/12/iOS-4.2.1-untethered-jailbreak-with-Redsn0w-0.9.7b1-225x300.jpg[/img]
Jailbreak your iPhone 4, iPad or iPod Touch 4G with Redsn0w 0.9.6 b4 for Mac.

Now Open Cydia and check whether you have Signature Hash files for iOS 4.2b3 saved on Cydia server. If so, proceed to the next step.
Download Redsn0w 0.9.7b1 here

Download usbmuxd.

Extract usbmuxd file, and start Mac OS X Terminal app from Applications> Utilities folder.

Now point the Terminal app to the python-client directory in usbmuxd folder and enter the commands in each line.

chmod +x tcprelay.py
./tcprelay.py -t 22:2222

Usbmuxd will make the Apple USB cable work with the jailbreak application. Make sure that you enter the commands exactly as shown above.

Run Redsn0w 0.9.7b1 and point it to the official iOS 4.2.1 firmware file.

Click next, select Jailbreak Monte option and browse to the downloaded iOS 4.2.1 beta 3.

Redsn0w 0.9.7b1 will now process jailbreak and in the next step choose the option Jailbreak Monte (untether).

Now enter into the DFU mode by following the on screen instructions.

Redsn0w 0.9.7b1 will complete the jailbreak process and will start your device in the untethered mode.

This version of Redsn0w is a little unstable, and therefore, some device options may stop working after jailbreak. So normal users and those who rely on the Ultrasn0w unlock are not advised to use this jailbreak. Redsn0w 0.9.7b2 or the upcoming versions of the tool would be able to process the untethered jailbreak with locally saved Signature Hash files and without usbmuxd.

Update: Download Redsn0w 0.9.7b3 here. (Install Redsn0w 0.9.7b3 after a fresh restore with iOS 4.2.1)

Bugs fixed: Native app crashes with Redsn0w 0.9.7b2, Issues with embedded videos and FaceTime with Redsn0w 0.9.7b3.

Update: Download Redsn0w 0.9.7b4 here. Now you don’t need to use usbmuxd and any related command part for jailbreaking. Just follow the other steps given in the tutorial and finally use Redsn0w 0.9.7b4 for untethered jailbreak.

Update: Download Redsn0w 0.9.7b5 here. Bluetooth issues are now fixed.

Update: Download Redsn0w 0.9.7b6 here. Issues with Skype fixed.

Related posts:

Restore Cydia apps from backup after iOS jailbreak
Download Ultrasn0w 1.2 unlock for iOS 4.2.1
Unlock iPhone 3G and 3G S firmware
Download Redsn0w 0.9.6b6 and activate iPhone 3G or 3GS with SAM
Apple iOS 4.0 iPhone and iPod touch are available for download