| Acronym | Definition |
|---|---|
| TCP | Transmission Control Protocol |
| UDP | Uniform Datagram Protocol; Layer 4 |
| IP | Internet Protocol; Layer 3 |
| IPv4 | Internet Protocol version 4; 32 Bits; Dotted Decimal format |
| ICMP | Internet Control Message Protocol |
| ARP | Address Resolution Protocol; Discovers network devices on a LAN; Records MAC Addresses of LAN. |
| DHCP | Dynamic Host Configuration Protocol; Dynamically assigns IP, DNS, and subnet mask to network devices. Ports 67, 68. |
| APIPA | Automatic Private IP Addressing. Assigned to Windows OS's if DHCP fails. 169.254.0.0-169.254.255.255 |
| NAT | Network Address Translation; Translates between IP addresses of different networks. Typically between private and public IP networks. |
| PAT | Port Address Translation (Aka NAT Overload). Type of NAT that uses 1 to many IP translations by utilizing layer 4 port numbers. |
| RIP | Routing Information Protocol. Basic, distance vector routing protocol. |
| BGP | Border Gateway Protocol; Exterior Gateway routing protocol used for exchanging routing information between network systems. Typically found at the ISP level. |
| OSPF | Open Shorteset Path First; Link-state routing protocol. |
| EIGRP | Enhanced Interior Gateway Routing Protocol; Cisco distance-vector routing protocol. |
| SSH | Secure Shell; Port 22 |
| NTP | Network Time Protocol; port 123 |
| TFTP | Trivial File Transfer Protocol; Port 69 |
| HTTP | Hypertext Transfer Protocol; Port 80 |
| HTTPS | Hypertext Transfer Protocol + SSL/TLS; Port 443 |
| FTP | File Transfer Protocol; Ports 20 and 21 |
| SMTP | Simple Mail Transfer Protocol; Port 25 |
| POP3 | Post Office Protocol; Port 110 |
| DNS | Domain Name Server/Service; Port 53 |
| Telnet | Unencrypted; Port 23 |
| SNMP | Simple Network Management Protocol; Port 161 |