Unit 5: Interfaces and Breakout Ports

Per-unit concept, checklist, and command drill page

Unit 5 of 14

Objective

Configure and validate physical and logical interfaces, counters, rates, and breakout behavior.

Concept Notes

Interface validation is the first line of defense for performance anomalies. Before analyzing overlays or routing, verify basic link behavior, negotiated settings, and error counters.

Breakout changes are high-impact operations because they alter both physical lane mapping and logical naming. Always pair breakout actions with explicit post-change verification and config persistence checks.

Coverage Checklist

Interface taxonomy: swp, eth0, loopback, bridge, bond, VLAN subinterfaces, VRF.
Admin/carrier/oper state interpretation.
Link properties: speed, MTU, duplex, FEC, auto-negotiation.
Counters, rates, and error telemetry interpretation.
Breakout modes, naming transformation, and reversion.
Persistent interface state and bulk operations.

Practice Outcomes

Validate state transitions and persistence across reboot windows.
Detect physical faults quickly through counter and error view correlation.
Plan breakout changes without introducing naming/config mismatch.

Command Drills

nv show interface

Inspect operational and admin state and properties.

nv show interface swp1 counters errors

Investigate drops and faults at interface level.

nv action clear interface counters

Reset baseline before controlled testing.

nv set interface swp16 link breakout 4x200G && nv config apply

Apply breakout for high-density link scenarios.

Navigation

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