CONNECT ERROR: Couldn't resolve host 'magento-community'

If you are trying to install any 3rd party extensions from your magento connect manager and getting such an error,

“CONNECT ERROR: Couldn't resolve host 'magento-community'”

Then the reason is the Magento Connect is not able to detect the download channel.

You will need to change the Magento Connect Version 1.0 to 2.0 when getting the extension key from magento extension page Or this can be installed using new connect manager by changing the extension key format.

For example: magento-community/Mage_myModule needs to be changed to http://connect20.magentocommerce.com/community/Mage_myModule