E. Well-Known TCP/UDP Port Numbers
Port numbers are divided into three ranges: Well Known Ports, Registered
Ports, and Dynamic and/or Private Ports. Well Known Ports are those
from 0 through 1023. Registered Ports are those from 1024 through 49151.
Dynamic and/or Private Ports are those from 49152 through 65535.
Well Known Ports are assigned by IANA, and on most systems, can only
be used by system processes or by programs executed by privileged
users. Table below shows some of the well-known port numbers. For
more details, please visit the IANA website:
http://www.iana.org/assignments/port-numbers
Port
Number
Protocol
TCP/UDP
21
FTP (File Transfer Protocol)
TCP
22
SSH (Secure Shell)
TCP
23 Telnet
TCP
25
SMTP (Simple Mail Transfer Protocol)
TCP
37 Time
TCP,
UCP
39
RLP (Resource Location Protocol)
UDP
49 TACACS,
UDP
53 DNS
UDP
67 BOOTP
server
UDP
68 BOOTP
client
UDP
69 TFTP
UDP
70 Gopher
TCP
79 Finger
TCP
80 HTTP
TCP
110 POP3
TCP
119
NNTP (Network News Transfer Protocol)
TCP
161/162 SNMP
UDP
443 HTTPS
TCP