An airport authority uses route-maps to attach BGP communities that later drive whether traffic exits early (hot-potato) or rides farther (cold-potato). What role do those communities play?
Select an answer to reveal the explanation.
Short Explanation
Communities are colored tags on a suitcase. The airport sticks ‘prefer-exit-west’ on a prefix; downstream policy sees the tag and sets LOCAL_PREF or MED accordingly. The tag itself isn’t the metric—it’s the signal that triggers policy.
Full Explanation
BGP communities are policy markers carried with routes so operators can classify prefixes and apply consistent actions (LOCAL_PREF, MED, filtering, aggregation behavior) via route-maps. They enable scalable hot-potato versus cold-potato designs without per-prefix manual treatment everywhere. Communities do not replace OSPF costing or L2 CoS, nor are they a mandatory ASN rewrite mechanism. Treat them as the signaling layer of routing policy.