Port

TCP

UDP

Description

9

UDP

Wake-on-LAN

20

TCP

UDP

FTP data transfer

21

TCP

FTP control (command)

22

TCP

UDP

Secure Shell (SSH) — used for secure logins, 
file transfers (scp, sftp) and port forwarding

23

TCP

UDP

Telnet protocol—unencrypted text communications

25

TCP

Simple Mail Transfer Protocol (SMTP)
used for e-mail routing between mail servers

42

TCP

UDP

Windows Internet Name Service

53

TCP

UDP

Domain Name System (DNS)

57

TCP

Mail Transfer Protocol (RFC 780)

67

UDP

Bootstrap Protocol (BOOTP) Server; 
also used by Dynamic Host Configuration Protocol (DHCP)

68

UDP

Bootstrap Protocol (BOOTP) Client; 
also used by Dynamic Host Configuration Protocol (DHCP)

69

UDP

Trivial File Transfer Protocol (TFTP)

80

TCP

Hypertext Transfer Protocol (HTTP)

88

TCP

UDP

Kerberos—authentication system

115

TCP

Simple File Transfer Protocol (SFTP)

119

TCP

Network News Transfer Protocol (NNTP)
—retrieval of newsgroup messages

123

UDP

Network Time Protocol (NTP)—used for time synchronization

135

TCP

UDP

DCE endpoint resolution

135

TCP

UDP

Microsoft EPMAP (End Point Mapper), 
also known as DCE/RPC Locator service,[15] 
used to remotely manage services 
including DHCP server, DNS server and WINS.

137

TCP

UDP

NetBIOS NetBIOS Name Service

138

TCP

UDP

NetBIOS NetBIOS Datagram Service

139

TCP

UDP

NetBIOS NetBIOS Session Service

143

TCP

Internet Message Access Protocol (IMAP)—
management of email messages

161

UDP

Simple Network Management Protocol (SNMP)

162

TCP

UDP

Simple Network Management Protocol Trap (SNMPTRAP)[18]

389

TCP

UDP

Lightweight Directory Access Protocol (LDAP)

401

TCP

UDP

UPS Uninterruptible Power Supply

443

TCP

Hypertext Transfer Protocol over TLS/SSL (HTTPS)

445

TCP

Microsoft-DS Active Directory, Windows shares

445

TCP

Microsoft-DS SMB file sharing

464

TCP

UDP

Kerberos Change/Set password

530

TCP

UDP

RPC

543

TCP

klogin, Kerberos login

544

TCP

kshell, Kerberos Remote shell

546

TCP

UDP

DHCPv6 client

547

TCP

UDP

DHCPv6 server

636

TCP

UDP

Lightweight Directory Access Protocol over TLS/SSL (LDAPS)

647

TCP

DHCP Failover protocol[24]

989

TCP

UDP

FTPS Protocol (data): FTP over TLS/SSL

1812

TCP

UDP

radius, RADIUS authentication protocol

1813

TCP

UDP

radacct, RADIUS accounting protocol

3389

TCP

UDP

Microsoft Terminal Server (RDP)

6600

TCP

Microsoft Hyper-V Live