I'm writing a migration using migrate/migrate_d2d to import nodes from one Drupal 7 installation to another.
Currently there are a lot of links on the web that point to articles using the example.com/node/[nid] url. Since the site I'm importing to will eventually replace the current one, I need to make sure those links still point to the correct articles.
How can I preserve nids during the migration, so that the old links that use /node/[nid] still point to the correct articles?
Alternatively, how can I easily make 500,000+ URLs to old nids redirect to their newly migrated counterpart?