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Ethernet connection (variant -E, -EF) DIQ/S 28X
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6.6 Technical network terms
DHCP
(Dynamic Host Config-
uration Protocol)
DHCP is a network service which automatically assigns an IP address
to a network subscriber.
In local networks, this function is mostly carried out by the router.
DNS
(Domain Name Sys-
tem)
DNS is a network service which manages the name of a subscriber
on the Internet (e.g. www.google.com) and the associated IP address
e.g. "http://74.125.224.72/".
In local networks, this function is mostly carried out by the router.
DynDNS
(Dynamic DNS)
DynDNS is an Internet service which makes a subscriber with
changing (dynamically issued) IP address accessible under a fixed
name on the Internet.
Prerequisite: The router in the local network must support DynDNS
and must always send its current dynamic public IP address to the
Internet service.
Firewall A firewall protects a device or a local network against attacks from the
Internet.
A firewall blocks the communication interfaces (ports) that are not
used for standard communication (web browser, E-mail etc.).
IP address A network address identifies a subscriber in a network.
Private IP addresses are IP addresses specially reserved for home
networks (range 192.168.0.0 to 192.168.255.255). In most cases,
they are automatically assigned by the router which manages the
local network. They are used to uniquely identify the individual
subscribers within a local network.
Routers provide the possibility to manually assign a fixed local IP
address for individual devices.
Public IP addresses are automatically assigned to the router in the
local network (LAN) by the Internet Service Provider (ISP). They are
used to uniquely identify an Internet subscriber (a home network or
even an individual device) to the Internet. They are mostly only valid
for the duration of an Internet session (dynamic IP address) and are
released again upon ending the Internet connection.
An Internet user can also be assigned a fixed public IP address via
(chargeable) Internet services.
ISP
(Internet Service Pro-
vider)
An ISP is an Internet service provider which provides Internet access.