1. Pick a name
www.example.com
mail.example.com
www.example.org
2. Ask the resolver
Look up
Reset
3. Let time pass
+1 minute
+10 minutes
+1 day
What the resolver remembers
Answer
Time left
Example TTLs: ending servers 2 days, domain servers 1 day, address 5 minutes. Delays in ms are illustrative.