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.
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