RewriteEngine On
RewriteRule ^isp/?([^-]+)$ http://new-site-domain/isp/$1 [P]
RewriteRule ^isp$ http://www.old-site-domain/isp/? [L]
RewriteRule ^/?(.*) http://new-site-domain/$1 [P]
Not Found
The requested URL /index.html was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.