常见的服务及端口概览

远程连接

Service	Port	Transport Protocol
Telnet	23（明文传输，极不安全）	TCP/UDP
SSH	22	TCP/UDP/SCTP
Windows Remote Desktop	3389	TCP

文件传输

Service	Port	Transport Protocol
TFTP	69	UDP
FTP	21	TCP/UDP/SCTP
SFTP	115	TCP/UDP

E-mali

Service	Port	Port for SSL	Transport Protocol
IMAP	143	993	TCP/UDP
SMTP	25	994/465	TCP/UDP
POP3	110	995	TCP

Web

Service	Port	Transport Protocol
HTTP	80	TCP/UDP
HTTPS	443	TCP/UDP/SCTP
http-alt	8080	TCP/UDP

数据库

Service	Port	Transport Protocol
Microsoft SQL Server	TCP 1433	TCP
Microsoft SQL Server	TCP 3306	TCP

VPN

Service	Port	Transport Protocol
PPTP	1723	TCP
L2TP	1701	UDP
IPSec	500/4500	UDP

网络

Service	Port	Transport Protocol
Whois	43	TCP/UDP
Domain Name Server	53	TCP/UDP
Network Time Protocol	123	TCP/UDP
NETBIOS Name Service	137/138/139	TCP/UDP
syslog	514	UDP