3.7. Summary of Recommendations
Depending on the scenario, an ISP or enterprise AS operator should follow one of the following recommendations concerning uRPF/SAV:

For directly connected networks, i.e., subnets directly connected to the AS, the AS under consideration SHOULD perform ACL-based SAV.
For a directly connected single-homed stub AS (customer), the AS under consideration SHOULD perform SAV based on the strict uRPF method.
For all other scenarios:

The EFP-uRPF method with Algorithm B (see Section 3.4) SHOULD be applied on customer interfaces.
The loose uRPF method SHOULD be applied on lateral peer and transit provider interfaces.
It is also recommended that prefixes from registered ROAs and IRR route objects that include ASes in an ISP's customer cone SHOULD be used to augment the pertaining RPF lists (see Section 3.5 for details).