Table 145: Common TCP/IP Well-Known Port Numbers and Applications
Port #
|
TCP /
UDP
|
Keyword
|
Protocol
Abbreviation
|
Application
or Protocol Name / Comments
|
7
|
TCP + UDP
|
echo
|
|
Echo Protocol
|
9
|
TCP
+ UDP
|
discard
|
|
Discard
Protocol
|
11
|
TCP + UDP
|
systat
|
|
Active Users
Protocol
|
13
|
TCP
+ UDP
|
daytime
|
|
Daytime
Protocol
|
17
|
TCP + UDP
|
qotd
|
QOTD
|
Quote Of The
Day Protocol
|
19
|
TCP
+ UDP
|
chargen
|
|
Character
Generator Protocol
|
20
|
TCP
|
ftp-data
|
FTP (data)
|
File Transfer
Protocol (default data port)
|
21
|
TCP
|
ftp
|
FTP
(control)
|
File
Transfer Protocol (control / commands)
|
23
|
TCP
|
telnet
|
|
Telnet Protocol
|
25
|
TCP
|
smtp
|
SMTP
|
Simple
Mail Transfer Protocol
|
37
|
TCP + UDP
|
time
|
|
Time Protocol
|
43
|
TCP
|
nicname
|
|
Whois
Protocol (also called Nicname)
|
53
|
TCP + UDP
|
domain
|
DNS
|
Domain Name
Server (Domain Name System)
|
67
|
UDP
|
bootps
|
BOOTP
/ DHCP
|
Bootstrap
Protocol /
Dynamic Host Configuration Protocol (Server)
|
68
|
UDP
|
bootpc
|
BOOTP / DHCP
|
Bootstrap Protocol
/
Dynamic Host Configuration Protocol (Client)
|
69
|
UDP
|
tftp
|
TFTP
|
Trivial
File Transfer Protocol
|
70
|
TCP
|
gopher
|
|
Gopher Protocol
|
79
|
TCP
|
finger
|
|
Finger
User Information Protocol
|
80
|
TCP
|
http
|
HTTP
|
Hypertext Transfer
Protocol (World Wide Web)
|
110
|
TCP
|
pop3
|
POP
|
Post
Office Protocol (version 3)
|
119
|
TCP
|
nntp
|
NNTP
|
Network News
Transfer Protocol
|
123
|
UDP
|
ntp
|
NTP
|
Network
Time Protocol
|
137
|
TCP + UDP
|
netbios-ns
|
|
NetBIOS (Name
Service)
|
138
|
UDP
|
netbios-dgm
|
|
NetBIOS
(Datagram Service)
|
139
|
TCP
|
netbios-ssn
|
|
NetBIOS (Session
Service)
|
143
|
TCP
|
imap
|
IMAP
|
Internet
Message Access Protocol
|
161
|
UDP
|
snmp
|
SNMP
|
Simple Network
Management Protocol
|
162
|
UDP
|
snmptrap
|
SNMP
|
Simple
Network Management Protocol (Trap)
|
179
|
TCP
|
bgp
|
BGP
|
Border Gateway
Protocol
|
194
|
TCP
|
irc
|
IRC
|
Internet
Relay Chat
|
443
|
TCP
|
https
|
HTTP over SSL
|
Hypertext Transfer
Protocol over
Secure Sockets Layer
|
500
|
UDP
|
isakmp
|
IKE
|
IPSec
Internet Key Exchange
|
520
|
UDP
|
router
|
RIP
|
Routing Information
Protocol (RIP-1 and RIP-2)
|
521
|
UDP
|
ripng
|
RIPng
|
Routing
Information Protocol - Next Generation
|