сделал вот так, добавил в index.php
PHP код:
$linkRequest = $_SERVER['REQUEST_URI'];
if(preg_match("/.aspx$/",$linkRequest))
{
$toRedirect = preg_replace("/(.aspx$)/",".html", $linkRequest);
header('HTTP/1.1 301 Moved Permanently');
header('Location: http://www.site.ru'.$toRedirect);
exit();
}
либо
RewriteBase /
RewriteRule ^(.*)\.aspx$ $1.html [R=permanent,L]