There’s the ports everyone knows, like telnet and ftp but being out of the networking for a while i’ve forgotten some and I learned others
This was a good refreasher for me and I came away with some of the ports i hadn’t known.
Notes:
Telnet tcp/23
Nonencrypted, in the clear
SSH tcp/22
Encrypted
Looks and feel of telnet
DNS udp/53
Domain name to ipaddress
SMTP Simple Mail Transfer Protocol tcp/25
Email server
Used for outgoing mail
SFTP tcp/22 secure File transfer protocol
Uses SSH, that's why same port
Can resume interrupted transfers
Has remote file removal
Has directory listing
FTP tcp/20 (active mode data) tcp/21(control)
Transfers files
Has username/password
List, add, delete..
Tftp udp/69 trivial file transfer protocal
No login
Reads and writes
DHCP udp/67, udp/68 Dynamic Host Configuration Protocol
Required DHCP server
Pool of ip addresses
Has lease time and must renew ip at set intervals
DHCP reservations
Addresses are assigned by MAC address in DHCP server
Quickly Manage from 1 location
Servers, printers…
HTTP tcp/80 HTTPS tcp/443
Hyper text protocol
Communication in the browser
Can be used by other applications
HTTP = in the clear
HTTPS = encrypted
SNMP upd/161 Simple Network Management Protocol
Different versions
V.1 structured tables, in the clear
V.2 Data type enhancements, bulk transfers, still in clear
V.3 Message integrity, Authentication, encryption
Rdp tcp/3389 Remote Desktop Protocol
On many windows systems
Can connect to entire desktop or just application
Clients for Win, MAcOS, Linux, Unix, iPhone
NTP udp/123 Network Time Protocol
Sets time for device
Syncs all devices
Used for Authentication
You control when clocks are updated
Very Accurate (better then 1 millisecond on local network)
VOIP tcp/5060 and tcp/5061 (SIP Session Initiation Protocol)
Voice over IP Signaling
Doing all call
Adds video, instant messaging, file transfer
SMB Server Message Block tcp/445
Protocol used my Microsoft
File Sharing
Print Sharing
Also called CIFS (Common Internet File System)
PoP/Imap tcp/110 POP3
Basic Mail Transfer
IMAP4 tcp/143
Includes management of email inbox from multiple clients. (desktop and iPhone)
LDAP tcp/389 Lightweight Directory Access Protocol
Store and receive data in a network directory
LDAPS(LDAP Secure) tcp/636
Non-standard of ldap over SSL
H.323 tcp/1720
Also VOIP
ITU Telecommunication h.23 protocol series
Does all all call things
Early. But still used today.
