The Well Known Ports are controlled and assigned by the IANA and on most systems can only be used by system (or root) processes or by programs executed by privileged users.
Ports are used in the TCP [RFC793] to name the ends of logical connections
which carry long term conversations. For the purpose of providing services to unknown callers, a service contact port is defined.
This list specifies the port used by the server process as its contact port. The contact port is sometimes called the "well-known port". To the extent possible, these same port assignments are used with the UDP [RFC768].
The assigned ports use a small portion of the possible port numbers. For many years the assigned ports were in
the range 0-255. Recently, the range for assigned ports managed by the IANA has been expanded to the range 0-1023.
Keyword | Decimal | Description |
0/tcp | Reserved | |
0/udp | Reserved |
|
tcpmux | 1/tcp | TCP Port Service Multiplexer |
tcpmux | 1/udp |
TCP Port Service Multiplexer |
compressnet | 2/tcp | Management Utility |
compressnet |
2/udp | Management Utility |
compressnet | 3/tcp | Compression Process |
compressnet | 3/udp | Compression Process |
4/tcp | Unassigned | |
4/udp | Unassigned | |
rje | 5/tcp | Remote Job Entry |
rje | 5/udp | Remote Job Entry |
6/tcp | Unassigned | |
6/udp | Unassigned | |
echo | 7/tcp | Echo |
echo | 7/udp | Echo |
8/tcp |
Unassigned | |
8/udp | Unassigned | |
discard | 9/tcp | Discard |
discard | 9/udp |
Discard |
10/tcp | Unassigned | |
10/udp | Unassigned | |
systat | 11/tcp |
Active Users |
systat | 11/udp |
Active Users |
12/tcp | Unassigned | |
12/udp | Unassigned | |
daytime | 13/tcp | Daytime |
daytime | 13/udp | Daytime |
|
14/tcp | Unassigned | |
14/udp | Unassigned | |
15/tcp | Unassigned [was netstat] | |
15/udp | Unassigned | |
16/tcp | Unassigned | |
16/udp | Unassigned | |
qotd | 17/tcp | Quote of the Day |
|
qotd | 17/udp | Quote of the Day |
msp | 18/tcp | Message Send Protocol |
msp | 18/udp |
Message Send Protocol |
chargen | 19/tcp | Character Generator |
chargen | 19/udp | Character Generator |
ftp-data |
20/tcp | File Transfer [Default Data] |
ftp-data | 20/udp | File Transfer [Default Data] |
ftp | 21/tcp | File Transfer [Control] |
|
ftp | 21/udp | File Transfer [Control] |
ssh | 22/tcp | SSH Remote Login Protocol |
ssh | 22/udp |
SSH Remote Login Protocol |
telnet | 23/tcp | Telnet |
telnet | 23/udp | Telnet |
24/tcp | any private mail system | |
24/udp | any private mail system | |
smtp | 25/tcp |
Simple Mail Transfer |
smtp | 25/udp | Simple Mail Transfer |
26/tcp |
Unassigned | |
26/udp | Unassigned | |
nsw-fe | 27/tcp | NSW User System FE |
nsw-fe | 27/udp | NSW User System FE |
28/tcp | Unassigned | |
28/udp | Unassigned | |
msg-icp | 29/tcp | MSG ICP |
msg-icp | 29/udp | MSG ICP |
30/tcp | Unassigned | |
30/udp | Unassigned | |
|
msg-auth | 31/tcp | MSG Authentication |
msg-auth | 31/udp | MSG Authentication |
32/tcp | Unassigned | |
32/udp | Unassigned | |
dsp | 33/tcp | Display Support Protocol |
|
dsp | 33/udp | Display Support Protocol |
34/tcp | Unassigned | |
34/udp | Unassigned | |
35/tcp | any private printer server | |
35/udp | any private printer server | |
36/tcp | Unassigned | |
36/udp | Unassigned |
|
time | 37/tcp | Time |
time | 37/udp | Time |
rap | 38/tcp |
Route Access Protocol |
rap | 38/udp | Route Access Protocol |
rlp | 39/tcp | Resource Location Protocol |
rlp |
39/udp | Resource Location Protocol |
40/tcp | Unassigned | |
40/udp | Unassigned | |
graphics | 41/tcp | Graphics |
graphics | 41/udp | Graphics |
name |
42/tcp | Host Name Server |
name |
42/udp | Host Name Server |
nameserver | 42/tcp | Host Name Server |
|
nameserver | 42/udp | Host Name Server |
nicname | 43/tcp | Who Is |
nicname | 43/udp | Who Is |
mpm-flags | 44/tcp |
MPM FLAGS Protocol |
mpm-flags | 44/udp | MPM FLAGS Protocol |
mpm | 45/tcp | Message Processing Module [recv] |
mpm |
45/udp | Message Processing Module [recv] |
mpm-snd | 46/tcp | MPM [default send] |
|
mpm-snd | 46/udp | MPM [default send] |
ni-ftp | 47/tcp | NI FTP |
ni-ftp | 47/udp | NI FTP |
auditd | 48/tcp | Digital Audit Daemon |
auditd | 48/udp |
Digital Audit Daemon |
tacacs | 49/tcp | Login Host Protocol (TACACS) |
tacacs | 49/udp | Login Host Protocol (TACACS) |
re-mail-ck |
50/tcp | Remote Mail Checking Protocol |
re-mail-ck | 50/udp | Remote Mail Checking Protocol |
|
la-maint | 51/tcp | IMP Logical Address Maintenance |
la-maint | 51/udp | IMP Logical Address Maintenance |
xns-time | 52/tcp |
XNS Time Protocol |
xns-time | 52/udp | XNS Time Protocol |
domain | 53/tcp | Domain Name Server |
domain |
53/udp | Domain Name Server |
xns-ch | 54/tcp | XNS Clearinghouse |
xns-ch | 54/udp | XNS Clearinghouse |
isi-gl | 55/tcp | ISI Graphics Language |
isi-gl | 55/udp | ISI Graphics Language |
xns-auth | 56/tcp | XNS Authentication |
xns-auth | 56/udp |
XNS Authentication |
57/tcp | any private terminal access | |
57/udp | any private terminal access | |
xns-mail | 58/tcp | XNS Mail |
xns-mail | 58/udp | XNS Mail |
59/tcp | any private file service | |
59/udp | any private file service | |
60/tcp | Unassigned | |
|
60/udp | Unassigned | |
ni-mail |
61/tcp | NI MAIL |
ni-mail | 61/udp | NI MAIL |
acas | 62/tcp | ACA Services |
|
acas | 62/udp | ACA Services |
whois++ | 63/tcp | whois++ |
whois++ | 63/udp | whois++ |
covia | 64/tcp |
Communications Integrator (CI) |
covia | 64/udp | Communications Integrator (CI) |
tacacs-ds | 65/tcp | TACACS-Database Service |
tacacs-ds |
65/udp | TACACS-Database Service |
sql*net | 66/tcp | Oracle SQL*NET |
sql*net | 66/udp | Oracle SQL*NET |
bootps | 67/tcp | Bootstrap Protocol Server |
bootps | 67/udp | Bootstrap Protocol Server |
bootpc | 68/tcp | Bootstrap Protocol Client |
bootpc | 68/udp |
Bootstrap Protocol Client |
tftp | 69/tcp | Trivial File Transfer |
tftp | 69/udp | Trivial File Transfer |
gopher |
70/tcp | Gopher |
gopher | 70/udp | Gopher |
netrjs-1 | 71/tcp | Remote Job Service |
|
netrjs-1 | 71/udp | Remote Job Service |
netrjs-2 | 72/tcp | Remote Job Service |
netrjs-2 | 72/udp |
Remote Job Service |
netrjs-3 | 73/tcp | Remote Job Service |
netrjs-3 | 73/udp | Remote Job Service |
netrjs-4 |
74/tcp | Remote Job Service |
netrjs-4 | 74/udp | Remote Job Service |
75/tcp | any private dial out service | |
75/udp | any private dial out service | |
deos |
76/tcp | Distributed External Object Store |
deos | 76/udp | Distributed External Object Store |
77/tcp | any private RJE service | |
77/udp | any private RJE service | |
vettcp | 78/tcp | vettcp |
vettcp | 78/udp | vettcp |
finger | 79/tcp | Finger |
finger | 79/udp | Finger |
|
http | 80/tcp | World Wide Web HTTP |
http | 80/udp | World Wide Web HTTP |
www | 80/tcp | World Wide Web HTTP |
www | 80/udp | World Wide Web HTTP |
www-http | 80/tcp | World Wide Web HTTP |
www-http |
80/udp | World Wide Web HTTP |
hosts2-ns | 81/tcp | HOSTS2 Name Server |
hosts2-ns | 81/udp | HOSTS2 Name Server |
|
xfer | 82/tcp | XFER Utility |
xfer | 82/udp | XFER Utility |
mit-ml-dev | 83/tcp | MIT ML Device |
mit-ml-dev | 83/udp | MIT ML Device |
ctf | 84/tcp | Common Trace Facility |
ctf | 84/udp | Common Trace Facility |
mit-ml-dev |
85/tcp | MIT ML Device |
mit-ml-dev | 85/udp | MIT ML Device |
mfcobol | 86/tcp | Micro Focus Cobol |
|
mfcobol | 86/udp | Micro Focus Cobol |
87/tcp | any private terminal link | |
87/udp | any private terminal link | |
kerberos | 88/tcp | Kerberos |
kerberos | 88/udp | Kerberos |
|
su-mit-tg | 89/tcp | SU/MIT Telnet Gateway |
su-mit-tg | 89/udp | SU/MIT Telnet Gateway |
dnsix | 90/tcp |
DNSIX Securit Attribute Token Map |
dnsix | 90/udp | DNSIX Securit Attribute Token Map |
mit-dov |
91/tcp | MIT Dover Spooler |
mit-dov | 91/udp | MIT Dover Spooler |
npp | 92/tcp | Network Printing Protocol |
|
npp | 92/udp | Network Printing Protocol |
dcp | 93/tcp | Device Control Protocol |
dcp | 93/udp |
Device Control Protocol |
objcall | 94/tcp | Tivoli Object Dispatcher |
objcall | 94/udp | Tivoli Object Dispatcher |
supdup |
95/tcp | SUPDUP |
supdup | 95/udp | SUPDUP |
dixie | 96/tcp | DIXIE Protocol Specification |
|
dixie | 96/udp | DIXIE Protocol Specification |
swift-rvf | 97/tcp | Swift Remote Virtural File Protocol |
swift-rvf | 97/udp |
Swift Remote Virtural File Protocol |
tacnews | 98/tcp | TAC News |
tacnews | 98/udp | TAC News |
metagram |
99/tcp | Metagram Relay |
metagram | 99/udp | Metagram Relay |
newacct | 100/tcp | [unauthorized use] |
|
hostname | 101/tcp | NIC Host Name Server |
hostname | 101/udp | NIC Host Name Server |
iso-tsap | 102/tcp |
ISO-TSAP Class 0 |
iso-tsap | 102/udp | ISO-TSAP Class 0 |
gppitnp | 103/tcp | Genesis Point-to-Point Trans Net |
gppitnp |
103/udp | Genesis Point-to-Point Trans Net |
acr-nema | 104/tcp | ACR-NEMA Digital Imag. & Comm. 30 |
|
acr-nema | 104/udp | ACR-NEMA Digital Imag. & Comm. 30 |
cso | 105/tcp | CCSO name server protocol |
cso | 105/tcp |
CCSO name server protocol |
csnet-ns | 105/tcp | Mailbox Name Nameserver |
csnet-ns | 105/udp | Mailbox Name Nameserver |
3com-tsmux |
106/tcp | 3COM-TSMUX |
3com-tsmux | 106/udp | 3COM-TSMUX |
rtelnet | 107/tcp | Remote Telnet Service |
|
rtelnet | 107/udp | Remote Telnet Service |
snagas | 108/tcp | SNA Gateway Access Server |
snagas | 108/udp |
SNA Gateway Access Server |
pop2 | 109/tcp | Post Office Protocol - Version 2 |
pop2 | 109/udp | Post Office Protocol - Version 2 |
pop3 |
110/tcp | Post Office Protocol - Version 3 |
pop3 | 110/udp | Post Office Protocol - Version 3 |
|
sunrpc | 111/tcp | SUN Remote Procedure Call |
sunrpc | 111/udp | SUN Remote Procedure Call |
mcidas | 112/tcp |
McIDAS Data Transmission Protocol |
mcidas | 112/udp | McIDAS Data Transmission Protocol |
ident |
113/tcp | |
auth | 113/tcp | Authentication Service |
auth |
113/udp | Authentication Service |
audionews | 114/tcp | Audio News Multicast |
audionews | 114/udp | Audio News Multicast |
|
sftp | 115/tcp | Simple File Transfer Protocol |
sftp | 115/udp | Simple File Transfer Protocol |