## Interdomain routing policies - Influence of peering link type

Consider the network below where the red arrows represent customer->provider peerings and the blue lines shared cost peerings. We consider different policies for the green line.

Provide your answer as a comma-separated list of paths starting with the preferred one. For example, the answer:

AS9:AS1, AS8:AS7:AS1


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.

##### Question 1: Interdomain paths

What are the interdomain paths that AS3 has learned to reach the prefix advertised by AS1 in the network above if AS2 is a shared-cost peer of AS3 ?

##### Question 2: Interdomain paths

What are the interdomain paths that AS3 has learned to reach the prefix advertised by AS1 in the network above if AS2 is a customer of AS3 ?

##### Question 3: Interdomain paths

What are the interdomain paths that AS3 has learned to reach the prefix advertised by AS1 in the network above if AS2 is a provider of AS3 ?