Drupal Internal links don't work after migration

In some cases, after migrating all internal links in drupal defaults to the homepage. If you encounter this issue, enable mod_rewrite in Apache.

For Ubuntu users,

sudo a2enmod rewrite

Restart Apache

sudo /etc/init.d/apache2 restart

 
You can also.......
(a) make sure that you have Drupal's .htaccess file
(b) make sure that the apache vhost which controls your site does not contain an AllowOverrides None which disables .htaccess files in your site's directory. Change it to AllowOverrides All