Follow a Message through a Router

Supplied materials

• Paper and pencil; answers may also be spoken or typed.
• All cases, labels, numbers and rules are supplied on this page. No real account, private information or purchase is needed.

Learn the idea

A router forwards data between connected paths. It is not the message’s final reader. The supplied network diagram names the sender, intermediate router and destination. Following each link shows whether a route exists. This simplified diagram does not describe every real routing decision.

Trace the connected links from the sender to the named destination. A nearby device is not reachable if the required link is missing.

Use this supplied case: Message starts at A and is for B. Map: A connects to R; R connects to B and C; D is isolated. Which route fits? Use the details in this example. Say which detail helped you choose. This pretend example does not tell us how every real system works.

1. Follow the worked example one step at a time. Say or draw what happens.
2. Trace the connected links from the sender to the named destination.
3. Say which detail makes the example answer fit. Pick another answer and say why it does not fit.
4. Try the question and practice questions. Read the rule again if your answer does not match the explanation.

Check your reasoning

Your answer is temporary and is not saved to an account. Download your current answer before leaving or reloading. Written work on paper or in another app stays in your own file.

Take it further

New map: P→R→Q; node S isolated. Expected: P can reach Q through R and no supplied route reaches S. Name each traversed link.

Nothing here is saved to an account or sent to a teacher. The answer download includes your current choice and any checked feedback. It does not include choices from the separate More practice section. Download that section separately.