Great post on getting rid of PHPSESSID problems, including a script to re-direct indexed URL’s.

www.frozenminds.com/disable-sessionid.html

Looks like Channel 4 has a little duplication problem at the moment on their IP address http://83.98.28.10/. It’s resulting in double listing with the domain and the IP ranking for some queries which we know Google doesn’t like.

In total around 8,000 pages of 6,390,000 pages of Channel 4′s site have this problem which I’m sure isn’t having a massive negative effect in the grand scheme of things.

All that’s needed is a 301 re-direct from the IP address to the domain. On apache servers this can be done with something along the lines of

RewriteEngine on
RewriteCond %{HTTP_HOST} =999.999.999.999
RewriteRule ^(.*) http://www.domain.com/$1 [R=301,L]