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Siemens Web server OZW672... V4.0 CE1C5712en
Building Technologies Appendix 28.08.2012
NAT
NAT is a method to translate IP addresses (private IP addresses) in a network into
one or several public IP addresses on the Internet. NAT allows us to use several
network devices in a LAN together with a public IP address of a router for Internet
access.
The network devices of the local network are masked by the IP address (router)
registered on the Internet. Thanks to this security function, NAT often is used as a
part of a network's firewall. Web server is accessible from a public network thanks
to the correct NAT table definition; see also port forwarding.
Network A network (LAN, WAN) is a linked group of devices connected via various lines
or radio sharing common resources such as data or peripheral devices.
Network adapter
Hardware to connect network components to a local area network (LAN).
Connection can be wired or wireless.
Network Address
Translation See NAT
Network configuration
All settings an IP-based device requires to work on a network: IP address, subnet
mask, standard gateway, preferred DNS server, and alternate DNS server.
PAT PAT or NPAT (Network and Port Address Translation) translates all private network
addresses into one public (dynamic) IP address. In this process, port numbers are
exchanged in addition to addresses when there is a connection. As a result, an
entire private network only requires one single registered public IP address.
Plant room
The ISP provides the connection to the Internet via DSL or cable TV (at a fee).
Point-to-Point Protocol See PPP
Port Ports are used to exchange data between different applications on a network. The
port number addresses the application within a network device. The combination
of IP address and port number serves as a unique identification of the recipient or
the sender of the data package with the network.
Internet service applications work with set port numbers (HTTP 80, FTP 21).
See
Port numbers 0 to 49151 are set and reserved, port numbers 49152 to 65535 are
dynamic (and therefore available).
Port and Address
Translation See PAT
Port Forwarding With port forwarding, the router forwards data packages from the Internet, destined
for a particular port, to the port of the responsible network device. As a result, serv-
ers (web server) integrated in a LAN, can be reached from the Internet (without a
need for a public IP address). Port Forwarding is achieved by the correct NAT /
PAT definition in the router.
PPP Protocol for dial-up connection of a computer to the ISP.
PPP over Ethernet See PPPoE