After having a similar problem several years ago, I found it much better to point everything to one
domain name, and to use the canonical form " www.domain_name.tld/ " for all incoming links. On-site
links can be canonical or relative - that didn't seem to matter.
If, for some reason, your server doesn't "find" index.php when looking for "/" you can use mod_dir
in .htaccess or any other redirect to fix this in one single spot, rather than hunting down and
changing a bunch of links.
Jim