Can't Download iOS 5.1? Try These Fixes
Mar 9, 2012 - 19 Comments
iOS 5.1 was released a few days ago but some people are still having problems when trying to update. The download can time out, not start at all, or sometimes throw an error message saying "Unable to Check for Update. An error occurred while checking for a software update." or "The network connection could not be established."
If you're having trouble downloading iOS 5.1 from Apple's servers, try these fixes:
Reset Network Settings on iOS Device: Tap Settings > General > Reset > Reset Network Settings
Clear Hosts File: Look at your hosts file for anything blocking Apple's servers and comment them out, this is mostly relevant to jailbreakers and if you see "Error 3194"
Change DNS Servers: Adjusting DNS on either the computer you are downloading from or iOS device if using OTA can resolve the issue, instructions on how to do so are below
Changing DNS seems to be the most reliable method, here is how to do so in iOS and OS X.
Changing DNS in iOS
Tap on Settings, tap on "Wi-Fi", and tap on the blue arrow next to the router name
Under "DHCP" tab tap on "DNS" and replace with: "8.8.8.8″ for Google DNS, or "208.67.222.222″ for OpenDNS
Tap the Back button and attempt to use OTA again
Change DNS in OS X
Open System Preferences from the Apple menu
Click on "Network" and then click on 'Advanced' in the lower right corner
Click the "DNS" tab and then add a new DNS server by clicking the "+" icon, adding either "8.8.8.8″ for Google DNS or "208.67.222.222″ for OpenDNS
Drag the newly added DNS server to the top of the list, click "OK" then close out of System Preferences
On a Mac you may need to follow this up with flushing DNS cache, so open the Terminal and type the following:
dscacheutil -flushcache
Now try opening iTunes and updating, or try to download iOS 5.1 firmware directly from Apple again.
An unrelated but pleasant side effect of changing DNS can be that your wi-fi speeds increase, give it a try and let us know if it works for you.
Thanks to Aygie and Sayed for the DNS tips!