Hack the Route Start free Open app Dynamic routing
Route leak
Routes announced past where they should go: a customer passing on a transit's routes, or a mistyped more-specific.
Since the longest prefix wins before any BGP preference, a leaked /25 pulls traffic for its half of a /24 to whoever leaked it. Defences: a prefix list on each customer allowing only the blocks it holds, and an export policy that announces to transits and peers only your own and your customers' routes (often by community). Not the same as VRF route leaking, which copies routes between tables on purpose.