This paper presents a proposal for shrinking the number of IPv4 FIB (Forwarding Information Base) entries required on routers. Traffic forwarding under the proposed mechanism is based on the current ASNs (Autonomous System Numbers), and can be gradually adopted by ISPs.We find that, at the cost of adding 8 bytes per packet, the proposed ASN-FWD technique is capable of providing full IPv4 traffic forwarding based on ASN information, which is correspondent to 10% of the current number of IPv4 prefixes present on FIB of routers. Among its main benefits, the proposed approach alleviates the pressure on the amount of FIB shipped on routers, and paves the way for a worldwide adoption of IPv6260267COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL...