Think it through together · A little story
The robot discovers that one domain name can look up several addresses, and one server address can serve several websites.
Lay out the process
- One domain nameCan have multiple addresses
- One addressCan host multiple sites
- DNS and service configurationWork together to determine what you reach
A domain name and an IP address do not always have a one-to-one relationship.
Several addresses can serve the same domain to share traffic or provide redundancy. A single address can also serve multiple websites, distinguished using information in application protocols.
It is more accurate to think of a domain name as an entry point than as the permanent name of one machine.
Your turn to try
If two friends look up the same domain and get different IP addresses, must one of them have made a mistake?
Have you thought it through? Open for an explanation
Not necessarily. A service may correctly return different addresses. Check the domain’s configuration and the access situation to understand why.
Take away one discovery
A domain name and an IP address do not always have a one-to-one relationship.
Try covering the diagram above and explaining each step to someone in your family. If one step is hard to explain, go back and look at that card again.