Networking & IP Glossary
Plain-English definitions of the networking and IP terms you'll meet across IP Animals — from IP address and subnet to DNS, NAT and ASN. Search or jump straight to a term.
IP address #
A unique numeric label assigned to each device on a network, used to route data to and from it. Comes in two versions: IPv4 and IPv6. Learn more →
IPv4 #
The fourth version of the Internet Protocol, using 32-bit addresses written as four numbers 0–255 (e.g. 192.0.2.1). About 4.3 billion addresses exist. Learn more →
IPv6 #
The newest Internet Protocol, using 128-bit addresses written in hexadecimal (e.g. 2001:db8::1). It provides a practically unlimited supply of addresses. Learn more →
Public IP address #
The internet-facing address assigned to your network by your ISP. It's what websites see, and what IP Animals shows you. Learn more →
Private IP address #
An address used only inside a local network (e.g. 192.168.x.x), not routable on the public internet. Defined by RFC 1918. Learn more →
Static IP address #
An IP address that stays the same over time, usually manually configured or reserved for servers. Learn more →
Dynamic IP address #
An address assigned automatically (usually by DHCP) that can change over time. Most home connections use dynamic IPs. Learn more →
Subnet #
A logical subdivision of an IP network, letting one network be split into smaller, isolated segments. Learn more →
Subnet mask #
A 32-bit value (e.g. 255.255.255.0) that marks which part of an IP address is the network and which is the host. Learn more →
CIDR #
Classless Inter-Domain Routing — a notation like 192.168.0.0/24 where the number after the slash is how many bits identify the network. Learn more →
Prefix length #
The /number in CIDR notation, indicating how many leading bits of an address are the network portion. Learn more →
Wildcard mask #
The bitwise inverse of a subnet mask (e.g. 0.0.0.255), used in Cisco ACLs and OSPF.
Default gateway #
The router address a device sends traffic to when the destination is outside its own subnet.
DNS #
The Domain Name System — the internet's directory that translates names like example.com into IP addresses. Learn more →
A record #
A DNS record that maps a hostname to an IPv4 address. Learn more →
AAAA record #
A DNS record that maps a hostname to an IPv6 address. Learn more →
CNAME record #
A DNS record that makes one hostname an alias of another. Learn more →
MX record #
A DNS record specifying the mail servers responsible for a domain's email, with priorities. Learn more →
TXT record #
A flexible DNS record holding text, commonly used for SPF, DKIM and domain verification. Learn more →
PTR record #
A DNS record mapping an IP address back to a hostname — the basis of reverse DNS. Learn more →
Reverse DNS #
Looking up the hostname associated with an IP address, using PTR records under in-addr.arpa or ip6.arpa. Learn more →
DHCP #
Dynamic Host Configuration Protocol — automatically assigns IP addresses and network settings to devices as they join a network. Learn more →
NAT #
Network Address Translation — lets many devices on a private network share one public IP address. Learn more →
Port #
A 16-bit number (0–65535) identifying a specific service or connection on a device, like 443 for HTTPS. Learn more →
Ephemeral port #
A temporary, high-numbered port (typically 49152–65535) a client uses for the local end of a connection. Learn more →
TCP #
Transmission Control Protocol — a reliable, ordered, connection-based transport used for the web, email and file transfer. Learn more →
UDP #
User Datagram Protocol — a fast, connectionless transport with no delivery guarantees, used for DNS, video and games. Learn more →
ICMP #
Internet Control Message Protocol — used for diagnostics and error messages; the basis of ping and traceroute. Learn more →
Ping #
A tool that sends ICMP echo requests to measure whether a host is reachable and how long the round trip takes. Learn more →
Traceroute #
A tool that maps the sequence of routers (hops) packets pass through to reach a destination. Learn more →
Packet #
A small, self-contained unit of data with a header and payload; large data is split into many packets to cross the internet. Learn more →
MTU #
Maximum Transmission Unit — the largest packet size (in bytes) a link can carry, commonly 1500 on Ethernet.
MAC address #
A 48-bit hardware identifier burned into a network interface, written as six hex pairs (e.g. 00:1a:2b:3c:4d:5e). Learn more →
Router #
A device that forwards data between different networks and directs traffic toward its destination. Learn more →
ISP #
Internet Service Provider — the company that connects you to the internet and assigns your public IP. Learn more →
ASN #
Autonomous System Number — a unique ID for a network under a single administration, used in internet routing. Learn more →
BGP #
Border Gateway Protocol — how independent networks exchange routing information to form the global internet. Learn more →
Anycast #
A routing method where one IP address is announced from many locations, so users reach the nearest one. Learn more →
Unicast #
Communication addressed to a single specific recipient — the most common traffic type.
Multicast #
Communication delivered to a group of interested recipients at once.
Broadcast #
Communication sent to every device on a local network segment.
Loopback #
The address a device uses to refer to itself — 127.0.0.1 for IPv4 or ::1 for IPv6. Learn more →
Localhost #
The hostname for the loopback address, meaning 'this computer'. Learn more →
TTL #
Time To Live — a counter that limits how long a packet or DNS record lives before being discarded or refreshed.
Latency #
The time it takes for data to travel from source to destination, usually measured in milliseconds. Learn more →
Bandwidth #
The maximum rate at which data can be transferred over a connection, usually in Mbps or Gbps. Learn more →
HTTP #
HyperText Transfer Protocol — the protocol browsers use to request and receive web pages. Learn more →
HTTPS #
HTTP secured with TLS encryption, shown by the padlock in your browser. Learn more →
TLS #
Transport Layer Security — the encryption protocol (formerly SSL) that protects data in transit. Learn more →
VPN #
Virtual Private Network — encrypts all your traffic and routes it through a server, hiding your IP from sites. Learn more →
Proxy #
A server that makes requests on your behalf, so the destination sees the proxy's IP instead of yours. Learn more →
Tor #
The Onion Router — routes traffic through several volunteer relays to hide who is communicating with whom. Learn more →
WHOIS / RDAP #
Protocols for looking up registration data about a domain or IP address; RDAP is the modern successor to WHOIS. Learn more →
IP geolocation #
Estimating the approximate physical location of an IP address from databases — accurate only to a city or region. Learn more →
Firewall #
A security system that filters network traffic based on rules, blocking unwanted connections.
LAN / WAN #
Local Area Network (a home or office network) versus Wide Area Network (a network spanning large distances, like the internet).
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