Tunnel failure error or DNS error in BlackBerry

Please provide proper APN name in your BB


Steps to locate APN are as follows:


Options->Device-> Advanced System Settings->TCP/IP->Enable APN Settings
APN: "TATA.DOCOMO.INTERNET" (for tata) OR "www" (for vodafone) OR (Service provider APN name)


If this does not solve the problem
The simplest way to correct this error is to turn WiFi off, and use the device's cellular connection instead. 


If switching from WiFi to cellular does not help, it might be necessary to change application permissions in the BlackBerry.
From the BlackBerry's main menu, select Options.
From the Options menu, select Advanced Options.
From the Advanced Options menu, select Applications.
From the Application menu, select your application and press the menu key.
Select "Edit Permissions."
Press the menu button and select "Reset Firewall Prompts."
Connections, Interactions, and User Data must all be set to Allow. If they are set to Custom, press the "A" key on the BlackBerry. This will change the setting from Custom to Allow.
Press the menu key and select "Save."
Back out to the Options menu. Select "Security Options."
Select "Firewall."
Be sure that Status is set to "Disabled."
Be sure that none of the boxes under the heading "Block Incoming Messages" are checked. If any are, uncheck them.
Press the menu key and select "Save."
Back all the way out of the Options menu, and try the Epocrates update process again.


If you still encounter the "tunnel failed" error, it might be necessary to reset the BlackBerry's browser settings.
Open "Options."
From Options, select "Advanced Options."
From Advanced Options, select "Browser."
Set the default to "Internet Browser."
Press the menu button and select "Save."