Bom amigo, para bloquear deve-se primeiro marcar o que queremos bloquear... nesse caso. Espero que agora o código completo possa lhe ajudar:
Código :
/ip firewall mangle add chain=prerouting p2p=all-p2p action=mark-connection new-connection-mark=conn-p2p passthrough=yes comment="CONTROLE DO P2P" disabled=no add chain=prerouting connection-mark=conn-p2p action=mark-packet new-packet-mark=pacotes-p2p passthrough=yes comment="" disabled=no add chain=prerouting p2p=all-p2p action=mark-routing new-routing-mark=p2p passthrough=no comment="" disabled=no /ip firewall filter add chain=forward p2p=all-p2p src-address-list=!p2p-sem-bloqueio action=drop comment="BLOQUEIO DO P2P" disabled=yes