Should you use a 302 redirect to a temporary alias for the new server during a DNS update?

For the scenario described—moving a website to a new server while keeping its original URL, then deleting a temporary alias a few days later—the supplied public discussions lean toward getting the website running on the new server first, then changing DNS and keeping the old site available during the transition, rather than using a 302 redirect to a temporary alias. The reasoning is that visitors might bookmark an alias that will soon stop working, and search engines might index it during that period. However, these are risks and recommendations raised by discussion participants, not grounds for claiming that a 302 redirect necessarily harms rankings. Nor should a TTL of 300 seconds be presented as a guarantee that the old site can safely be shut down after five minutes.

Focus on keeping the website available, rather than changing the URL visitors see

One answer about changing a website’s IP address focuses on avoiding downtime: confirm that the website is running at the second IP address, then update DNS, and wait a few days before shutting down the old server. Applied to this migration, that suggests the following sequence:

1. Get the website running on server B first; do not wait until after the DNS switch to start deployment.
2. Update the original domain’s DNS to point to B.
3. Keep A running during the transition so that visitors still reaching the old server can access the website.
4. Following that answer’s recommendation, shut down A a few days later; “a few days” is an operational recommendation, not a universal guarantee.

This approach assumes that the new site is ready to serve visitors and that the old site can remain available during the transition. If A must be shut down immediately, the material does not provide a complete alternative that can be used directly.

The problem with a temporary alias is that people may keep using it

The proposed approach would redirect visitors still reaching A from the original URL to B’s hosting-provider alias. An answer opposing this approach raises two specific concerns:

• Bookmark risk: New visitors might bookmark the alias. If it is deleted a few days later, that bookmark may no longer take them back to the website.
• Search risk: If Google visits during the transition, it might index the temporary alias.

For example, if a visitor bookmarks the alias on the day of the move, that bookmark will still open the alias later. It will not turn into the original URL just because the original domain’s DNS switch is complete. As for search impact, the material only raises the possibility of indexing. It provides no ranking changes, test results, or official search engine guidance, so it cannot support a claim that rankings will definitely drop or that there will definitely be no effect.

300 seconds is five minutes, but that alone does not establish that a migration is complete

The original question does state that the TTL has been set to 300 seconds, and a respondent therefore recommends waiting five minutes without using a redirect. That time conversion is correct, but the answer does not provide enough information to establish that all visitors will have switched over. It should therefore not be the sole basis for shutting down A.

The common direction of these discussions is to use DNS to switch the original URL to a new site that is already ready. “Wait five minutes” and “shut down the old site a few days later” are operational recommendations from different answers; they should not be combined into a precise, universally applicable schedule.