What is the main difference between TCP and UDP
TCP is the connection-based( reliable)
udp is connectionless. (faster but less reliable)
Tcp is guaranteed delivery like web emails UDP for gaming and streaming
what are ports 20 -21 used for
FTP (file transfer protocol) - transfers files between systems over TCP
still used in legacy systems , insecure unless encrypted
What is port 22 used for ?
SSH (secure shell) - secure remote login and command line access via TCP
why it matters - admis use it daily to control systems security
what is port 23 used for ?
Telnet- remote command line access (insecure , TCP(SSH replacement)
outdated and insecure, replace by SSH. know it to avoid using it
what is port 25 used for
SMTP (simple mail transfer protcol) - sends email (TCP)
its how messages leave your email app
what is port 53 used for
DNS (domain name systems)- translate domain names to IPS and vise versa uses TCP and UDP
without DNS you would have to remember IPS to browse the NET
what are ports 67 / 68 used for
DHCP ( dynamic host configuration protocol) - assigns IPs to devices (UDP)
No DHCP= manual IP setup= pain
what is port 80 used for
HTTP -transfer web pages over TCP (non - secure).
Basis of web browsing before HTTPS
What is port 110 used for
POP3 ( post office protocol 3) - downloads emails to device (TCP)
Legacy emails method still in use
what is port 143 used for ?
IMAP - manges email on server (TCP)
Most modern emails clients use this to sync across devices
what are ports 137-139 used for
NetBios/NETBT - Legacy windows file / printer sharing (tcp/udp_.
legacy systems still use this ; be cations for security
what is port 389 used for
LDAP -accesses directory services (TCP/UDP)
used for authentications ( like logging into a work computer)
What is port 443 used for
HTTPS -secure web traffic (TCP)
standard for modern , secure browsing
what is 445 used for
SMB/CIFS - windows file / printer sharing over TCP
still used in windows networks today
what is port 3389 used for
RDP- remote desktop protocol (TCP/UDP)
used for remote control of desktops (especially in IT)
