Consider the simple interdomain network shown below where we will look at the impact of the routing policies on the link between
AS4 on the paths towards the prefix advertised by
AS1 that are received by
Provide your answers as a comma-separated list of paths starting with the preferred one. For example, the answer:
indicates that the AS has learned two different paths. The preferred one is the one via
AS9 that has a length of 2 AS hops while the second path has a length of 3 AS hops. If there is no path, return 0 as your answer.