Glossary
Multi-Tech Systems, Inc. RouteFinder RF850/860 User Guide (PN S000400E)
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IP Address
– A 32-bit number that identifies the devices using the IP protocol. An IP address can be unicast,
broadcast, or multicast. See RFC 791 for more information. Every host has a clear IP address, comparable with
a telephone number. An IP address consists of four decimal numbers between 1 and 254, divided by dots (e.g.,
a possible IP address is 212.6.145.0. At least one name of the form xxx belongs to every IP address (e.g. xxx).
This defines a computer with the name ox that is in the sub domain xxx of the sub domain xxx of the domain
xxx. Like with IP addresses, the individual name parts are divided by dots. However, as opposed to IP
addresses, IP names are not limited to four parts. Also, several IP names can be assigned to one IP address;
these are referred to as aliases.
IP Header
– The part of the IP packet that carries data used on packet routing. The size of this header is 20
bytes, but usually the IP options following this header are also calculated as header. The maximum length of the
header is 60 bytes. The header format is defined in RFC 791.
IP Packet
– A self-contained independent entity of data carrying sufficient information to be routed from the
source to the destination computer without relying on any earlier exchange between this source and destination
computer and the transporting network. The Internet Protocol (IP) is defined in RFC 791.
IP Payload
– The part of the IP packet that carries upper level application data.
IPSec (IP Security)
– A set of IETF standards that provide authentication and encryption for IP-based and
Internet-based VPNs.
Key
– A data string which, when combined with source data (packet) using a special algorithm, produces output
that cannot be read without that specific key. Key data strings are typically 40-168 bits in length.
Key Agreement
– A process used by two or more parties to agree upon a secret symmetric key.
Key Exchange
– A process used by two more parties to exchange keys in cryptosystems.
Key Generation
– The act or process of creating a key.
Key Management
– The various processes that deal with the creation, distribution, authentication, and storage
of keys.
Key Pair
– Full key information in a public-key cryptosystem; consists of the public key and private key.
L2TP
(
Layer Two Tunneling Protocol
)
– A security protocol that facilitates the tunneling of PPP packets
across an intervening network in a way that is highly-transparent to both end-users and applications. L2TP is
defined in IETF RFC 2661.
LILO (LInux LOader)
– LILO is a small program that sits on the master boot record of a hard drive or on the
boot sector of a partition. LILO is used to start the loading process of the Linux kernel. (There are other
programs that can also do this, such as
grub
. Most distributions/versions of Linux use LILO.) You can set up lilo
to require a password to start to load the Linux kernel, or you can set it up to require a password if you want to
pass any extra options to the Linux kernel before it starts loading.
Mapping
– Logically associating one set of values (such as addresses on one network) with values or quantities
on another set (such as devices on another network). Examples include name-address mapping, inter-network
route mapping, and DNAT port mapping. Name resolution (name to address mapping) is another example.
Masquerading
– The concealing of internal network information (LAN) form the outside. For example, the
computer of a colleague with the IP address is inside a masked network. All the computers inside his network
are assigned one single, official IP address (i.e. if he starts an HTTP request into the Internet, his IP address is
replaced by the IP address of the external network card). This way, the data packet entering the external
network (Internet) contains no internal information. The answer to the request is recognized by the firewall and
diverted to the requesting computer.
MD5 (Message Digest 5)
– A one-way hashing algorithm that produces a 128-bit hash. It computes a secure,
irreversible, cryptographically strong hash value for a document. The MD5 algorithm is documented in IETF
RFC 1321.
Message Digests
– Mathematical functions (aka, one-way hashes) that are easy to compute but nearly
impossible to reverse. The message digest serves as a "fingerprint" for data. As such, it is an element of most
data security mechanisms (e.g., Digital Signatures, SSL, etc.). The hashing function takes variable-length data
as input, performs a function on it, and generates a fixed-length hash value.
