My original Joomla website created numerous URLs that related to the same dynamically generated product page. I have changed website platform (not domain) but the products are the same but now have have different urls. I dealt with the duplicates before using canonicals.
Now that I have changed the platform google is trying to crawl the old urls and obviously getting 404's.
Is it better to ignore this, and wait for google to stop, or redirect the old duplicate pages to a single new one?
eg. Old - www.yyy.com/product-details/product-101 Old - www.yyy.com/product-cat/www/product-101
301 redirect both to the new url of the product:
new - www.yyy.com/101-product