Why This Cheat Sheet Matters for ENCOR
This cheat sheet covers the most important OSPF Advanced concepts tested on the ENCOR (ENCOR) certification exam. It contains 2 sections with 12 key points that you should memorize before exam day. Use this as a quick-reference guide during your final review sessions.
2Sections
12Key Points
OSPF Area Types
- Backbone Area (Area 0): all areas must connect to Area 0.
- Standard Area: receives all LSA types.
- Stub Area: blocks type 5 LSAs (external). Uses default route instead.
- Totally Stubby Area: blocks type 3 + 5 LSAs. Only default route.
- NSSA: allows external routes as type 7 LSAs (converted to type 5 at ABR).
- Totally NSSA: blocks type 3 + 5, allows type 7. Default route injected.
LSA Types
- Type 1 (Router): generated by every router, stays within area.
- Type 2 (Network): generated by DR on multi-access networks.
- Type 3 (Summary): generated by ABR, inter-area routes.
- Type 4 (ASBR Summary): generated by ABR, path to ASBR.
- Type 5 (External): generated by ASBR, external routes.
- Type 7 (NSSA External): external routes within NSSA areas.
Practice OSPF Advanced Questions
Put your knowledge to the test with practice questions.
Cisco Command Quick Reference
Cisco IOS commands follow a hierarchical structure: User EXEC mode (>), Privileged EXEC mode (#), Global Configuration mode (config)#, and Interface Configuration mode (config-if)#. Master the transitions between these modes and the key "show" commands for each technology area — they are heavily tested on every Cisco exam.