Ports Flashcards (for CompTia Secuirty+ and General IT)

Ports 20/21

FTP (File Transfer Protocol) - (Unencrypted)

Port 22

SSH / SFTP / SCP (Secure Shell) - (Encrypted remote shell and file transfer)

Port 80

HTTP (Unencrypted web)

Port 443

HTTPS - (TLS/SSL encrypted web)

Port 23

Telnet - (Legacy unencrypted terminal access)

Port 3389

RDP (Remote Desktop Protocol) - (Windows graphical remote access)

Port 53

DNS (Domain Name System) - (UDP for standard lookups, TCP for zone transfers)

Ports 67/68

DHCP (Dynamic Host Configuration Protocol) - (UDP IP allocation)

Port 123

NTP (Network Time Protocol) - (Clock synchronization)

Port 49

TACACS+ (Device admin AAA protocol)

Ports 1812/1813

RADIUS (Network authentication)

Port 389

LDAP (Unencrypted directory services)

Port 636

LDAPS (Directory services over SSL/TLS)

Port 88

Kerberos (Active Directory ticket authentication)

Port 25

SMTP (Server mail relay)

Port 587

SMTP (Client submission via STARTTLS)

Port 110

POP3 / POP3S (Plaintext)

Port 995

POP3 / POP3S (Encrypted mail download)

Port 143

IMAP / IMAPS (Plaintext)

Port 993

IMAP / IMAPS (Encrypted mail access)

Ports 161/162

SNMP (Simple Network Management Protocol) - (UDP polling/traps; SNMPv3 is the secure version)

Port 514

Syslog (Unencrypted UDP logs)

Port 6514

Syslog - (Encrypted TCP via TLS)

Port 445

SMB (Server Message Block) - (Windows file/printer sharing)

Port 69

TFTP (Trivial File Transfer Protocol) - (UDP — lightweight, unencrypted file transfers with no authentication)

Ports 989/990

FTPS (FTP Secure) - (FTP over implicit SSL/TLS — distinct from SFTP on port 22)

Port 500

IPsec (Internet Protocol Security)- (UDP — used for VPN IKE key exchange)