Network and addresses
DNS record TTL
How many seconds a DNS record stays cached. It sets how fast an address change spreads.
TTL (time to live) tells resolvers how long to cache a record. With a TTL of 3600, some visitors keep reaching the old server for an hour after an address change.
Before moving to a new VPS, lower the TTL to 300 seconds a day in advance — then the change spreads in minutes.