Filter
Top Products
Appendix D. Definitions of terms
request a domain called, for instance, service. Below, we have ‘Company Inc.,’ which consists of three
departments: A sales department, a service department, and a computer department. The computer department
is divided into an IBM section and a Unisys section.
Contact your internet service provider to register a domain.
Dynamic routing
Dynamic routing is used when the traffic between two computers have several routes available. The route for
the packets can be changed if a connection is broken or a router is turned off. RIP is a protocol handling
dynamic routing.
Firewall
A device that prevents unauthorized access to a computer network.
Forwarding
See Relay.
FTP (File Transfer Protocol)
Imagine that you have an account on a UNIX machine. You can retrieve and store files on the UNIX machine
with FTP. The program that manages this is called the FTP server. You can also establish an area of files that
are accessible to others. Anyone can log in as user anonymous and enter his e-mail address as a password.
They can then access all files in this area, but nothing else. A computer with an FTP server and a freely
available area is usually called an FTP site.
Gateway
Gateway is an old name for a Router.
Hacker
A person who is skilled and knowledgeable about computers and likes to examine the details of a computer
system and what can be done with it. A hacker is good at programming and achieves good results. A hacker is
not to be confused with a computer criminal; see Cracker.
HTTPS
HTTPS is WWW traffic (HTTP traffic) on an encrypted connection. The encrypted connection is established
with the SSL protocol.
ICMP protocol
ICMP is used to forward information, primarily error messages. To see if a computer is running, the ‘ping’
program sends an echo request, which is part of ICMP. If a problem occurs with a connection, a response is
sent through ICMP that something is not right (the computer is not responding, the network is down, etc). If
there are two possible paths for a connection, a router along the way may tell the computer to use the other
path. The router sends an ICMP redirect. ICMP uses the IP protocol to send data over the network.
IP address
IP addresses are the Internet equivalent to telephone numbers. An IP address is divided into four groups, each
of which is a number from 0 to 255. The groups are separated by dots. An example of an IP address is
141