Why This Cheat Sheet Matters for ENCOR
This cheat sheet covers the most important Border Gateway Protocol concepts tested on the ENCOR (ENCOR) certification exam. It contains 2 sections with 14 key points that you should memorize before exam day. Use this as a quick-reference guide during your final review sessions.
2Sections
14Key Points
BGP Path Selection (in order)
- 1. Highest weight (Cisco proprietary, local to router).
- 2. Highest local preference (iBGP, default 100).
- 3. Locally originated routes.
- 4. Shortest AS-path.
- 5. Lowest origin type (IGP < EGP < Incomplete).
- 6. Lowest MED (Multi-Exit Discriminator).
- 7. eBGP over iBGP.
- 8. Lowest IGP metric to next hop.
- 9. Oldest eBGP route.
- 10. Lowest router ID.
Key Concepts
- eBGP: between different AS numbers. AD = 20.
- iBGP: within the same AS. AD = 200. Full mesh or route reflector required.
- BGP uses TCP port 179 for neighbor relationships.
- BGP is a path-vector protocol — prevents loops using AS-path.
Practice Border Gateway Protocol 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.