About
A port 1) has two definitions in computing.
It can be:
- logical: the number in a socket that locates a service for network protocol
- Physical (hardware): a way to connect devices together
This article talks about the logical netsocket port, the socket of the Internet Protocol.
NetSocket Port
The net socket is composed of:
- a IP address of the host
- the port
- and the type of net protocol (tcp or udp)
Example
For example, HTTP servers commonly use TCP port 80. When a port accepts a connection, it can be assumed that the commonly bound program is running.
Usage
The reason for having ports is that virtually all modern computers support multitasking. Thus, on a typical computer, there will be multiple programs that need to contact other programs on other computers over the network all at the same time. Ports enable multiple programs to share a single physical network connection simultaneously, as opposed to having only one program using the connection for a long period of time.
Protocol
The Internet protocols, both TCP and UDP support ports (65536 max) that programs can choose to bind to.
Port allows programs to run concurrently on one IP address.
Most programs have default ports that are most often used.
Number
The port number is the unique port identifier within a ip address
Port may also be used to describe an endpoint (ie the combination of a IP and a port)
Range
Port numbers have three ranges:
- System Ports (0-1023),
- User Ports (1024-49151),
- and the Dynamic and/or Private Ports (49152-65535);
The difference uses of these ranges is described in RFC 6335
State
Open
Binding
Which process is bound to which port ?
Forwarding
Well-known port numbers
Service Name and Transport Protocol Port Number Registry defines the well known port numbers of the Internet Assigned Numbers Authority (IANA) - responsible for the global coordination of the DNS Root, IP addressing, and other Internet protocol resources.
- email 25 and 487: What are the SMTP Ports? (25, 465, 587)
You can also find the well-known relationship port / services in the windows file C:\Windows\System32\drivers\etc\services
# Copyright (c) 1993-2004 Microsoft Corp.
#
# This file contains port numbers for well-known services defined by IANA
#
# Format:
#
# <service name> <port number>/<protocol> [aliases...] [#<comment>]
#
echo 7/tcp
echo 7/udp
discard 9/tcp sink null
discard 9/udp sink null
systat 11/tcp users #Active users
systat 11/udp users #Active users
daytime 13/tcp
daytime 13/udp
qotd 17/tcp quote #Quote of the day
qotd 17/udp quote #Quote of the day
chargen 19/tcp ttytst source #Character generator
chargen 19/udp ttytst source #Character generator
ftp-data 20/tcp #FTP, data
ftp 21/tcp #FTP. control
ssh 22/tcp #SSH Remote Login Protocol
telnet 23/tcp
smtp 25/tcp mail #Simple Mail Transfer Protocol
time 37/tcp timserver
time 37/udp timserver
rlp 39/udp resource #Resource Location Protocol
nameserver 42/tcp name #Host Name Server
nameserver 42/udp name #Host Name Server
nicname 43/tcp whois
domain 53/tcp #Domain Name Server
domain 53/udp #Domain Name Server
bootps 67/udp dhcps #Bootstrap Protocol Server
bootpc 68/udp dhcpc #Bootstrap Protocol Client
tftp 69/udp #Trivial File Transfer
gopher 70/tcp
finger 79/tcp
http 80/tcp www www-http #World Wide Web
hosts2-ns 81/tcp #HOSTS2 Name Server
hosts2-ns 81/udp #HOSTS2 Name Server
kerberos 88/tcp krb5 kerberos-sec #Kerberos
kerberos 88/udp krb5 kerberos-sec #Kerberos
hostname 101/tcp hostnames #NIC Host Name Server
iso-tsap 102/tcp #ISO-TSAP Class 0
rtelnet 107/tcp #Remote Telnet Service
pop2 109/tcp postoffice #Post Office Protocol - Version 2
pop3 110/tcp #Post Office Protocol - Version 3
sunrpc 111/tcp rpcbind portmap #SUN Remote Procedure Call
sunrpc 111/udp rpcbind portmap #SUN Remote Procedure Call
auth 113/tcp ident tap #Identification Protocol
uucp-path 117/tcp
sqlserv 118/tcp #SQL Services
nntp 119/tcp usenet #Network News Transfer Protocol
ntp 123/udp #Network Time Protocol
epmap 135/tcp loc-srv #DCE endpoint resolution
epmap 135/udp loc-srv #DCE endpoint resolution
netbios-ns 137/tcp nbname #NETBIOS Name Service
netbios-ns 137/udp nbname #NETBIOS Name Service
netbios-dgm 138/udp nbdatagram #NETBIOS Datagram Service
netbios-ssn 139/tcp nbsession #NETBIOS Session Service
imap 143/tcp imap4 #Internet Message Access Protocol
sql-net 150/tcp
sqlsrv 156/tcp
pcmail-srv 158/tcp #PCMail Server
snmp 161/udp #SNMP
snmptrap 162/udp snmp-trap #SNMP trap
print-srv 170/tcp #Network PostScript
bgp 179/tcp #Border Gateway Protocol
irc 194/tcp #Internet Relay Chat Protocol
ipx 213/udp #IPX over IP
rtsps 322/tcp
rtsps 322/udp
mftp 349/tcp
mftp 349/udp
ldap 389/tcp #Lightweight Directory Access Protocol
https 443/tcp MCom #HTTP over TLS/SSL
https 443/udp MCom #HTTP over TLS/SSL
microsoft-ds 445/tcp
microsoft-ds 445/udp
kpasswd 464/tcp # Kerberos (v5)
kpasswd 464/udp # Kerberos (v5)
isakmp 500/udp ike #Internet Key Exchange
crs 507/tcp #Content Replication System
crs 507/udp #Content Replication System
exec 512/tcp #Remote Process Execution
biff 512/udp comsat
login 513/tcp #Remote Login
who 513/udp whod
cmd 514/tcp shell
syslog 514/udp
printer 515/tcp spooler
talk 517/udp
ntalk 518/udp
efs 520/tcp #Extended File Name Server
router 520/udp route routed
ulp 522/tcp
ulp 522/udp
timed 525/udp timeserver
tempo 526/tcp newdate
irc-serv 529/tcp
irc-serv 529/udp
courier 530/tcp rpc
conference 531/tcp chat
netnews 532/tcp readnews
netwall 533/udp #For emergency broadcasts
uucp 540/tcp uucpd
klogin 543/tcp #Kerberos login
kshell 544/tcp krcmd #Kerberos remote shell
dhcpv6-client 546/tcp #DHCPv6 Client
dhcpv6-client 546/udp #DHCPv6 Client
dhcpv6-server 547/tcp #DHCPv6 Server
dhcpv6-server 547/udp #DHCPv6 Server
afpovertcp 548/tcp #AFP over TCP
afpovertcp 548/udp #AFP over TCP
new-rwho 550/udp new-who
rtsp 554/tcp #Real Time Stream Control Protocol
rtsp 554/udp #Real Time Stream Control Protocol
remotefs 556/tcp rfs rfs_server
rmonitor 560/udp rmonitord
monitor 561/udp
nntps 563/tcp snntp #NNTP over TLS/SSL
nntps 563/udp snntp #NNTP over TLS/SSL
whoami 565/tcp
whoami 565/udp
ms-shuttle 568/tcp #Microsoft shuttle
ms-shuttle 568/udp #Microsoft shuttle
ms-rome 569/tcp #Microsoft rome
ms-rome 569/udp #Microsoft rome
http-rpc-epmap 593/tcp #HTTP RPC Ep Map
http-rpc-epmap 593/udp #HTTP RPC Ep Map
hmmp-ind 612/tcp #HMMP Indication
hmmp-ind 612/udp #HMMP Indication
hmmp-op 613/tcp #HMMP Operation
hmmp-op 613/udp #HMMP Operation
ldaps 636/tcp sldap #LDAP over TLS/SSL
doom 666/tcp #Doom Id Software
doom 666/udp #Doom Id Software
msexch-routing 691/tcp #MS Exchange Routing
msexch-routing 691/udp #MS Exchange Routing
kerberos-adm 749/tcp #Kerberos administration
kerberos-adm 749/udp #Kerberos administration
kerberos-iv 750/udp #Kerberos version IV
mdbs_daemon 800/tcp
mdbs_daemon 800/udp
ftps-data 989/tcp #FTP data, over TLS/SSL
ftps 990/tcp #FTP control, over TLS/SSL
telnets 992/tcp #Telnet protocol over TLS/SSL
imaps 993/tcp #IMAP4 protocol over TLS/SSL
ircs 994/tcp #IRC protocol over TLS/SSL
pop3s 995/tcp spop3 #pop3 protocol over TLS/SSL (was spop3)
pop3s 995/udp spop3 #pop3 protocol over TLS/SSL (was spop3)
kpop 1109/tcp #Kerberos POP
nfsd-status 1110/tcp #Cluster status info
nfsd-keepalive 1110/udp #Client status info
nfa 1155/tcp #Network File Access
nfa 1155/udp #Network File Access
activesync 1034/tcp #ActiveSync Notifications
phone 1167/udp #Conference calling
opsmgr 1270/tcp #Microsoft Operations Manager
opsmgr 1270/udp #Microsoft Operations Manager
ms-sql-s 1433/tcp #Microsoft-SQL-Server
ms-sql-s 1433/udp #Microsoft-SQL-Server
ms-sql-m 1434/tcp #Microsoft-SQL-Monitor
ms-sql-m 1434/udp #Microsoft-SQL-Monitor
ms-sna-server 1477/tcp
ms-sna-server 1477/udp
ms-sna-base 1478/tcp
ms-sna-base 1478/udp
wins 1512/tcp #Microsoft Windows Internet Name Service
wins 1512/udp #Microsoft Windows Internet Name Service
ingreslock 1524/tcp ingres
stt 1607/tcp
stt 1607/udp
l2tp 1701/udp #Layer Two Tunneling Protocol
pptconference 1711/tcp
pptconference 1711/udp
pptp 1723/tcp #Point-to-point tunnelling protocol
msiccp 1731/tcp
msiccp 1731/udp
remote-winsock 1745/tcp
remote-winsock 1745/udp
ms-streaming 1755/tcp
ms-streaming 1755/udp
msmq 1801/tcp #Microsoft Message Queue
msmq 1801/udp #Microsoft Message Queue
radius 1812/udp #RADIUS authentication protocol
radacct 1813/udp #RADIUS accounting protocol
msnp 1863/tcp
msnp 1863/udp
ssdp 1900/tcp
ssdp 1900/udp
close-combat 1944/tcp
close-combat 1944/udp
nfsd 2049/udp nfs #NFS server
knetd 2053/tcp #Kerberos de-multiplexor
mzap 2106/tcp #Multicast-Scope Zone Announcement Protocol
mzap 2106/udp #Multicast-Scope Zone Announcement Protocol
qwave 2177/tcp #QWAVE
qwave 2177/udp #QWAVE Experiment Port
directplay 2234/tcp #DirectPlay
directplay 2234/udp #DirectPlay
ms-olap3 2382/tcp #Microsoft OLAP 3
ms-olap3 2382/udp #Microsoft OLAP 3
ms-olap4 2383/tcp #Microsoft OLAP 4
ms-olap4 2383/udp #Microsoft OLAP 4
ms-olap1 2393/tcp #Microsoft OLAP 1
ms-olap1 2393/udp #Microsoft OLAP 1
ms-olap2 2394/tcp #Microsoft OLAP 2
ms-olap2 2394/udp #Microsoft OLAP 2
ms-theater 2460/tcp
ms-theater 2460/udp
wlbs 2504/tcp #Microsoft Windows Load Balancing Server
wlbs 2504/udp #Microsoft Windows Load Balancing Server
ms-v-worlds 2525/tcp #Microsoft V-Worlds
ms-v-worlds 2525/udp #Microsoft V-Worlds
sms-rcinfo 2701/tcp #SMS RCINFO
sms-rcinfo 2701/udp #SMS RCINFO
sms-xfer 2702/tcp #SMS XFER
sms-xfer 2702/udp #SMS XFER
sms-chat 2703/tcp #SMS CHAT
sms-chat 2703/udp #SMS CHAT
sms-remctrl 2704/tcp #SMS REMCTRL
sms-remctrl 2704/udp #SMS REMCTRL
msolap-ptp2 2725/tcp #MSOLAP PTP2
msolap-ptp2 2725/udp #MSOLAP PTP2
icslap 2869/tcp
icslap 2869/udp
cifs 3020/tcp
cifs 3020/udp
xbox 3074/tcp #Microsoft Xbox game port
xbox 3074/udp #Microsoft Xbox game port
ms-dotnetster 3126/tcp #Microsoft .NET ster port
ms-dotnetster 3126/udp #Microsoft .NET ster port
ms-rule-engine 3132/tcp #Microsoft Business Rule Engine Update Service
ms-rule-engine 3132/udp #Microsoft Business Rule Engine Update Service
msft-gc 3268/tcp #Microsoft Global Catalog
msft-gc 3268/udp #Microsoft Global Catalog
msft-gc-ssl 3269/tcp #Microsoft Global Catalog with LDAP/SSL
msft-gc-ssl 3269/udp #Microsoft Global Catalog with LDAP/SSL
ms-cluster-net 3343/tcp #Microsoft Cluster Net
ms-cluster-net 3343/udp #Microsoft Cluster Net
ms-wbt-server 3389/tcp #MS WBT Server
ms-wbt-server 3389/udp #MS WBT Server
ms-la 3535/tcp #Microsoft Class Server
ms-la 3535/udp #Microsoft Class Server
pnrp-port 3540/tcp #PNRP User Port
pnrp-port 3540/udp #PNRP User Port
teredo 3544/tcp #Teredo Port
teredo 3544/udp #Teredo Port
p2pgroup 3587/tcp #Peer to Peer Grouping
p2pgroup 3587/udp #Peer to Peer Grouping
ws-discovery 3702/udp #WS-Discovery
ws-discovery 3702/tcp #WS-Discovery
dvcprov-port 3776/tcp #Device Provisioning Port
dvcprov-port 3776/udp #Device Provisioning Port
msfw-control 3847/tcp #Microsoft Firewall Control
msdts1 3882/tcp #DTS Service Port
sdp-portmapper 3935/tcp #SDP Port Mapper Protocol
sdp-portmapper 3935/udp #SDP Port Mapper Protocol
net-device 4350/tcp #Net Device
net-device 4350/udp #Net Device
ipsec-msft 4500/tcp #Microsoft IPsec NAT-T
ipsec-msft 4500/udp #Microsoft IPsec NAT-T
llmnr 5355/tcp #LLMNR
llmnr 5355/udp #LLMNR
wsd 5357/tcp #Web Services on devices
wsd 5358/tcp #Web Services on devices
rrac 5678/tcp #Remote Replication Agent Connection
rrac 5678/udp #Remote Replication Agent Connection
dccm 5679/tcp #Direct Cable Connect Manager
dccm 5679/udp #Direct Cable Connect Manager
ms-licensing 5720/tcp #Microsoft Licensing
ms-licensing 5720/udp #Microsoft Licensing
directplay8 6073/tcp #DirectPlay8
directplay8 6073/udp #DirectPlay8
man 9535/tcp #Remote Man Server
rasadv 9753/tcp
rasadv 9753/udp
imip-channels 11320/tcp #IMIP Channels Port
imip-channels 11320/udp #IMIP Channels Port
directplaysrvr 47624/tcp #Direct Play Server
directplaysrvr 47624/udp #Direct Play Server