Port Service 20 FTP-DATA 21 FTP 23 Telnet, Internet BBS 25 SMTP, Send mail 53 DNS 79 Finger 80 HTTP, World Wide Web 110 POP3, Receive mail 113 AUTH, Authentication 119 NNTP, Net News 139 NETBIOS Session Service 161 SNMP 162 SNMP-TRAP 443 HTTPS 500 ISAKMP 517 TALK 518 NTALK 1723 PPTP, Microsoft VPN 2049 NFS, Sun Network File System