Routing

Administrative Distance and Metrics

Learn how routers compare route candidates, distinguish administrative distance from metrics, and understand how redistribution, default routes, and parallel paths affect route selection.

Intermediate12 min read
Routing lessonNetworkingPractice

UNTIMED COACHING

Practice before the pressure

Use feedback to correct the model, not merely memorize an option position.

GUIDED PRACTICE

Practice the lesson questions

Answer normal lesson questions without a timer. Every answer includes an explanation, and incorrect answers can be tried again before continuing.

CONCEPT MODELS

See the lesson as a system

Use these visual guides to connect the key ideas before answering the questions.

How a router compares route candidatesRoute-source preference is considered before protocol-specific path ranking.
How a router compares route candidatesA flow showing route candidates compared by source preference, then by protocol metric.
Route candidatesSeveral paths reach one network
Administrative distanceRanks the information source
Protocol metricRanks paths within one protocol
Selected routeBest available path is installed
What happens across protocol boundariesRedistribution may require metric translation or a configured default value.
What happens across protocol boundariesA split model showing routes entering a receiving protocol through translation or a default metric.
Source protocolProduces its own path value
Redistribution boundaryMoves routes between protocols
Metric translationConverts values when supported
Default metricSupplies a receiving value