Glossary

DNSDomain Name System

DNS permits the assignment of IP addresses to computers or Domain names that are easier to remember. A DNS server must administer this information for each LAN with an Internet connection. As soon as a page on the Internet is called up, the browser obtains the corresponding IP address from the DNS server so that it can establish the connection.

On the Internet, the assignment of domain names to IP addresses follows a hierarchical system. A local PC only knows the address of the local name server. This in turn knows all the addresses of the PCs in the local network and the superordinate name servers, which again know addresses or the next superordinate name servers.

DNS serverSee DNSDomain name

The domain name is the reference to one or more Web servers on the Internet. The domain name is mapped via the DNS service to the corresponding IP address.

DoS attackDenial of Service

A DoS attack is a particular form of hacker attack directed at computers and networks with a connection to the Internet. The aim is not so much to steal data but to paralyse the computer or network so severely that the network resources are no longer available. A typical hacker attack involves making a remote computer announce that it is acting for the paralysed computer, for example, and receive the data intended for you.

DSLDigital Subscriber Line

DSL is a data transfer technique in which a connection to the Internet can be run at

1.5Mbps over normal telephone lines. A DSL connection is provided by an Internet serv- ice provider. It requires a DSL modem.

Dynamic IP address

A dynamic IP address is assigned to a network component automatically by DHCP. This means that the IP address of a network component can change with every login or at certain intervals.

See also: Static IP address

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