hosts file should be clean just 127.0.0.1 localhost
especially delete any antries that redirect l2authd.lineage2.com
As to ports, yes you can forward ports for supposed better performance in lineage but you dont have to forward ports in order to play. When I said make you sure you didnt mess with your firewall I meant in terms of blocking off l2.exe (if you are using sw firewall) or blocking off the lineage2.com iprange (if you are using hw firewall)
dont do that, leave the hosts file with the simple 127.0.0.1 localhost, Lineage2 doesnt need any specific IP. find whatever is beside l2authd.lineage2.com and DELETE it or mark it with a #