Well known decimal number system, represent any value with digit 0-9.
Usually used in lower and higher programming languages, known also as hexadecimal number system, represent any value with digit 0-9 and char A-F (case insensitive).
Representation of a value with 85 different digits/chars, this can lead to shorter strings but never seen in the wild.
Smallest storage unit, on/true (1) or off/false (0)
Mostly a collection of 8 (but not really a must - see older computer systems) bits
Here, hardware of network connection, see also NIC
A dual homed host is a node with two network (physical or virtual) interfaces on two different links, but does not forward any packets between the interfaces.
Generally a single homed host on a link. Normally it has only one active network interface, e.g. Ethernet or (not and) PPP.
Mostly same as “device”, see also NIC
Header of an IP packet (each network packet has a header, kind of is depending on network layer)
A link is a layer 2 network packet transport medium, examples are Ethernet, Token Ring, PPP, SLIP, ATM, ISDN, Frame Relay,...
A node is a host or a router.
A collection of 8 real bits, today also similar to “byte”.
Information for the TCP/UDP dispatcher (layer 4) to transport information to upper layers
Each network layer contains mostly a protocol field to make life easier on dispatching transported information to upper layer, seen in layer 2 (MAC) and 3 (IP)
A router is a node with two or more network (physical or virtual) interfaces, capable of forwarding packets between the interfaces.
An IP socket is defined by source and destination IP addresses and Ports and (binding)
Network related a collection of layers
IP networks uses bit masks to separate local networks from remote ones
A tunnel is typically a point-to-point connection over which packets are exchanged which carry the data of another protocol, e.g. an IPv6-in-IPv4 tunnel.
Access Control List
Application Programming Interface
Application Specified Integrated Circuit
Berkeley Software Distribution
Controller Area Network Bus (physical bus system)
Internet Service Provider
Project - a joint effort of six companies in Japan to provide a free IPv6 and IPsec (for both IPv4 and IPv6) stack for BSD variants to the world www.kame.net
Local Internet Registry
Network Interface Card
Request For Comments - set of technical and organizational notes about the Internet
UniverSAl playGround for Ipv6 Project - works to deliver the production quality IPv6 protocol stack for the Linux system.
The special character “¬” is used for signaling that this code line is wrapped for better viewing in PDF and PS files.
In generic examples you will sometimes find the following:
For real use on your system command line or in scripts this has to be replaced with relevant content (removing the < and > of course), the result would be e.g.
Commands executable as non-root user begin with $, e.g.
Commands executable as root user begin with #, e.g.