Apple's recent release of iOS 9 has been a fast one. In fact, Apple commented that it rolled out faster than any of the previous versions. However, it did not go without a hitch.
The Problem
Prior to the official iOS 9 release on Sept. 16, Cisco, a technology company that specializes in networking solutions, aired its concerns on how iOS 9 beta did not support AnyConnect, which is the company's proprietary multi-platform SSL (Secure Sockets Layer) VPN (Virtual Private Network) client that is aimed at, but not limited to, BYOD (Bring-Your-Own-Device) implementations that allow users to connect to their organization's VPN using their own devices, computers and mobile phones regardless of their location.
"We have noticed a couple of OS regressions between iOS 8.4.1 and iOS 9 which have been reported to Apple. Most notable is that when doing Split Tunneling, the Tunnel All DNS option no longer functions as expected. This was reported to Apple under Radar # 22558059," Cisco reported through a Facebook post released on Sept. 9. "This is not resolved in the iOS 9 release."
The DNS resolution failure is not limited to AnyConnect and is believed to affect other SSL VPN clients out in the market. Note that BYOD implementations for VPNs are adopted by a lot of businesses, hospitals, universities and people who want a more secure Internet experience.
In recent post, Cisco reported that AnyConnect is not having any problems on Mac OS X 10.11 (El Capitan). Thus, the glitch seems to be isolated on iOS 9.
Elaborating on VPN
For the uninitiated, VPNs encrypt the data that pass through them. Putting things in perspective, if the Internet is a highway and the packets of data are the automobiles passing on that highway, then a VPN is the option to tint the vehicles' windows. This prevents outsiders from knowing who or what is in each vehicle.
Hence, while the Internet service providers can see the packets of data going into a device, there is no way for them to know what the packets contains unless they break the encryption.
The Solution
The only reliable solution to this is by reverting back to iOS 8.4.1, which should be done through iTunes, and not iCloud.
To do this, the device must first be connected to iTunes. Once connected, the next step is locating the 'Restore Backup' button, which should be in the 'iTunes Summary'. Finally, Alt-clicking on the 'Restore Backup' button should bring up the available .ipsw files and if a corresponding one for 8.4.1 is still there, the downgrade can commence.
If the backup file does not exist, then you can thank Apple for wiping it. The other option would be to download the .ipsw file from Apple's online repositories. Note that with this option, however, the device will reset to factory settings
Photo: Bob Jouy | Flickr