DCops AI
Login
Menu

Protected

Cumulus supplement content is available after admin verification. Redirecting...

If you are not redirected, login.

Access

Admin only

The Cumulus supplement is restricted to admin users.

Training / NCP-AIN / Cumulus

Unit 12: BGP Overview

Per-unit concept, checklist, and command drill page

Unit 12 of 14

Objective

Master core BGP concepts, path selection, and ECMP requirements for scalable operations.

Concept Notes

BGP is both policy and scale. For exam readiness, avoid memorizing isolated commands; instead, reason from neighbor state to BGP decision process to kernel route outcomes.

When ECMP behavior is unexpected, start with attribute parity and best-path logic before assuming transport faults. Most “ECMP issues” are policy and attribute mismatches.

Coverage Checklist

  • AS and ASN model and neighbor session fundamentals.
  • EBGP vs IBGP design intent and constraints.
  • BGP databases: neighbors, RIB, and kernel FIB outcomes.
  • Path attributes and deterministic best-path selection.
  • ECMP tie conditions and operational implications.

Practice Outcomes

  • Explain how BGP attributes influence route preference in real incidents.
  • Identify when ECMP fails due to attribute mismatch.
  • Interpret route-table outcomes from neighbor state and policy.

Command Drills 

vtysh -c 'show bgp summary'

Check BGP session state and stability.

vtysh -c 'show ip bgp'

Inspect BGP RIB and path attributes.

vtysh -c 'show ip route bgp'

Validate selected BGP routes in FIB.

Navigation

Back to Cumulus index Previous: Unit 11 Next: Unit 13