FTP
File Transfer Protocol; Ports 20 and 21
Telnet
Unencrypted; Port 23
SMTP
Simple Mail Transfer Protocol; Port 25
TACACS+
Terminal Access Controller Access-Control System Plus; Port 49
DNS
Domain Name Server/Service; Port 53
HTTP
HTTP or Hyper Text Transfer Protocol; Port 80
HTTPS
HTTP or Hyper Text Transfer Protocol + Secure Socket Layer; Port 443
POP3 (v3)
Post Office Protocol; Port 110
IMAP
Internet Message Access Protocol; Port 143
SNMP
Simple Network management Protocol; Port 161
RDP
Remote Desktop Protocol; Port 3389
IPSEC
Internet Protocol Security; Tunneling Protocol that encrypts IP
IPSEC (Tunnel)
IPSEC in tunnel mode encrypts entire packet
IPSEC (Transport)
IPSEC in transport mode only encrypts data
PPP
Point to Point Protocol; Establishes layer 2 connection between two network devices
NAT
Network Address Translation. Translates IP addresses accross two different networks. Typically between a private and public IP network.
PAT
Port Address Translation (Aka NAT Overload); 1 to many NAT translation; Uses layer 4 ports to organize connections.
TLS
Transport Layer Security; Encryption protocol that replaced SSL; Commonly used by HTTPS on port 443
FTPS
File Transfer Protocol + SSL
SFTP
File Transfer Protocol + SSH
IPv4
Internet Protocol version 4; 32 bits; Dotted Decimal Format
IPv6
Internet Protocol version 6; 128 bits; Hexadecimal Format