Section 14: Ports and Protocols Flashcards
Port
Logical communication endpoint that exists on a computer or server
Inbound Port
Logical communication opening on a server that is listening for a connection from a client
Outbound Port
Logical communication opening created on a client in order to call out to a server that is listening for that connection
Well-Known Ports
Ports 0 to 1023 are considered well-known and are assigned by the Internet Assigned Numbers Authority (IANA)
Registered Ports
Ports 1024 to 49151 are considered registered and are usually assigned to proprietary protocols
Dynamic or Private Ports
Ports 49152 to 65535 can be used by any application without being registered with IANA
Port 20, 21
File Transfer Protocol (FTP)
Provides insecure file transfers
Port 22
Secure Shell (SSH)
Provides secure remote control of another machine using a text-based environment
Secure File Transfer Protocol (SFTP)
Provides secure file transfers
Port 23
Telnet
Provides insecure remote control of another machine using a text-based environment
Port 3389
RDP
Port 53
Domain Name System (DNS)
Converts domain names into IP addresses and vice versa
Port 67, 68
Dynamic Host Configuration Protocol (DHCP)
Automatically provides network parameters, such as assigned IP address, subnet mask, default gateway, and the DNS server
Port 80
Hypertext Transfer Protocol (HTTP)
Used for insecure web browsing
Port 110
Post Office Protocol Version Three (POP3)
Used for receiving incoming emails
Port 137, 139
Network Basic Input/Output System (NetBIOS)
Used for file or printer sharing in a Windows network
Port 143
Internet Mail Application Protocol (IMAP)
A newer method of retrieving incoming emails which improves upon the older POP3
Port 161, 162
Simple Network Management Protocol (SNMP)
Used to collect data about network devices and monitor their status
Port 389
Lightweight Directory Access Protocol (LDAP)
Used to provide directory services to your network
Port 443
Hypertext Transfer Protocol - Secure (HTTPS)
Used as a secure and encrypted version of web browsing, secured through SSL or TLS
Port 445
Server Message Block (SMB)
Used for Windows File and printer sharing services
Port 3389
Remote Desktop Protocol (RDP)
Provides graphical remote control of another client or server
Transmission Control Protocol (TCP)
Connection-oriented protocol, which means its a reliable way to transport segments across the network
a two way type of connection where you send information and wait for acknowledgement
3-way handshake:
CLIENT ————— SERVER
syn ->
<- syn ack
ack ->
“are you ready, yes I am, here it comes”
User Datagram Protocol (UDP)
unreliable and it transmit segments called datagrams.
Its a connectionless protocol because it doesnt wait for connections
