It’s difficult to get around Drupal-modules that appear to have the same functionality. This is particularly the case when you want to set-up decent SEO-friendly url’s. The two main modules are called “pathauto” (also named: url-alias) and “path-redirect” (also named: url-redirect). This post applies only to Drupal 6.
pathauto = url-alias = /admin/build/path/list = table url_alias
path-redirect = url-redirect = /admin/build/path-redirect/list = table path_redirect
PathAuto (or URL-alias)
Pathauto is the standard module that creates SEO-friendly URL’s for users, nodes, taxonomy (etc) based on the title of the node. You can set up what the url’s must look like in /admin/build/path/pathauto
But when an url gets changed, the previous url would become unreachable and the user would get a “404 – page not found”-error. This is negative for search engines, bookmarks, and links from other sites. This is where path-redirect comes to the rescue.
Path-Redirect (or URL-redirect)
The path-redirect module keeps a list of all aliases that were changes and redirects them with a 301 (the permanently moved http-status).
In order for this to work, you need to check an checkbox in path-redirect (see screenshot). Direct link: /admin/build/path-redirect/settings
As if that ain’t enough, you also have to specify this in PathAuto. Go to: /admin/build/path/pathauto and scroll to “General Settings” > “Update action”. Select “Create a new alias. Redirect from old alias” (see screenshot)