Continue your lesson
Follow traffic from the endpoint through each device, protocol, and service in the path.
Block 1 of 2Compare APIPA · RFC 1918 addressing · IPv4 loopback
Current · 15 min
Compare APIPA · RFC 1918 addressing · IPv4 loopback
Optional concept notes
APIPA
Self-assigns an IPv4 address from 169.254.0.0/16 after DHCP failure.
RFC 1918 addressing
Defines private IPv4 ranges that are not publicly routed.
IPv4 loopback
Tests the local TCP/IP stack within 127.0.0.0/8.
Complete one provider lesson, then answer four related questions. That is enough for today; more practice is optional.
Your lesson stays open here while the provider opens in another tab. Choose one source; the notes above are optional.
Block 2 of 2Understand Variable-length subnet masking
10 min
Understand Variable-length subnet masking
Optional concept notes
Variable-length subnet masking
Uses different prefix lengths to fit multiple subnet sizes.
Complete one provider lesson, then answer four related questions. That is enough for today; more practice is optional.
Your lesson stays open here while the provider opens in another tab. Choose one source; the notes above are optional.
Practice the reasoning here
Sketch a small network or packet path. Predict the expected state, introduce one fault, and identify the observation that isolates it.
- State the expected result before changing or testing anything.
- Name the observation, command, log, or report that would confirm it.
- Explain why the closest alternative does not fit the same requirement.
Check the whole objective
This unlocks objective 1.7 for recall. The latest checkpoint needs 70% or higher; a lower result puts the lesson back near the front of your timeline.