7. GLOSSARY AND ACRONYMS
The designers of the Internet Protocol defined an
IP address as a 32-bit number and this system,
known as Internet Protocol Version 4 (
IPv4
), is
still in use today. However, due to the enormous
growth of the Internet and the predicted deple-
tion of available addresses, a new version of IP
(
IPv6
), using 128 bits for the address, was de-
veloped in 1995.
IP masquerade
Kind of
NAT
.
IP masquerading
see
NAT
.
IPsec
Internet Protocol Security (IPsec) is a
protocol suite for securing Internet Protocol (IP)
communications by authenticating and encrypt-
ing each IP packet of a communication ses-
sion. The router allows user to select encap-
sulation mode (tunnel or transport), IKE mode
(main or aggressive), IKE Algorithm, IKE En-
cryption, ESP Algorithm, ESP Encryption and
much more. It is possible to create four different
tunnels.
IPv4
The Internet Protocol version 4 (IPv4) is
the fourth version in the development of the In-
ternet Protocol (IP) and the first version of the
protocol to be widely deployed. It is one of the
core protocols of standards-based internetwork-
ing methods of the Internet, and routes most traf-
fic in the Internet. However, a successor proto-
col,
IPv6
, has been defined and is in various
stages of production deployment. IPv4 is de-
scribed in IETF publication RFC 791 (September
1981), replacing an earlier definition (RFC 760,
January 1980).
IPv6
The Internet Protocol version 6 (IPv6) is
the latest revision of the Internet Protocol (IP),
the communications protocol that provides an
identification and location system for computers
on networks and routes traffic across the Inter-
net. IPv6 was developed by the Internet Engi-
neering Task Force (IETF) to deal with the long-
anticipated problem of IPv4 address exhaustion.
IPv6 is intended to replace
IPv4
, which still car-
ries the vast majority of Internet traffic as of
2013. As of late November 2012, IPv6 traffic
share was reported to be approaching 1%.
IPv6 addresses are represented as eight groups
of four hexadecimal digits separated by colons
(2001:0db8:85a3:0042:1000:8a2e:0370:7334),
but methods of abbreviation of this full notation
exist.
L2TP
Layer 2 Tunnelling Protocol (L2TP) is a
tunnelling protocol used to support virtual private
networks (
VPN
s) or as part of the delivery of ser-
vices by ISPs. It does not provide any encryption
or confidentiality by itself. Rather, it relies on an
encryption protocol that it passes within the tun-
nel to provide privacy.
LAN
A local area network (LAN) is a com-
puter network that interconnects computers in
a limited area such as a home, school, com-
puter laboratory, or office building using network
media. The defining characteristics of LANs, in
contrast to wide area networks (
WANs
), include
their usually higher data-transfer rates, smaller
geographic area, and lack of a need for leased
telecommunication lines.
NAT
In computer networking, Network Address
Translation (NAT) is the process of modifying
IP address information in IPv4 headers while in
transit across a traffic routing device.
The simplest type of NAT provides a one-to-one
translation of IP addresses. RFC 2663 refers to
this type of NAT as basic NAT, which is often also
called a one-to-one NAT. In this type of NAT only
the IP addresses, IP header checksum and any
higher level checksums that include the IP ad-
dress are changed. The rest of the packet is left
untouched (at least for basic TCP/UDP function-
ality; some higher level protocols may need fur-
ther translation). Basic NATs can be used to in-
terconnect two IP networks that have incompati-
ble addressing.
NAT-T
NAT traversal (NAT-T) is a computer
networking methodology with the goal to es-
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