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Virtual server – LevelOne FBR-1461 User Manual

Page 78

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Virtual Server

In TCP and UDP networks a port is a 16-bit number used to identify

which application program (usually a server) incoming connections

should be delivered to. Some ports have numbers that are

pre-assigned to them by the IANA (the Internet Assigned Numbers

Authorit

y), and these are referred to as “well-known ports”. Servers

follow the well-known port assignments so clients can locate them.

If you wish to run a server on your network that can be accessed

from the WAN (i.e. from other machines on the Internet that are

outside your local network), or any application that can accept

incoming connections (e.g. Peer-to-peer/P2P software such as

instant messaging applications and P2P file-sharing applications)

and are using NAT (Network Address Translation), then you need to

configure your router to forward these incoming connection attempts

using specific ports to the PC on your network running the application. You also need to use

port forwarding if you wish to host an online game server.

The reason is that when using NAT, your publicly accessible IP address is used by and

points to your router, which needs to deliver all traffic to the private IP addresses used by

your PCs. Please see the WAN configuration section of this manual for information on NAT.

The Internet Assigned Numbers Authority (IANA) is the central coordinator for the

assignment of unique parameter values for Internet protocols. Port numbers range from 0 to

65535, but only port numbers 0 to 1023 are reserved for privileged services and are
designated as “well-known ports”. The registered ports are numbered from 1024 through

49151. The remaining ports, referred to as dynamic ports, or private ports, are numbered

from 49152 through 65535.

Examples of well-known and registered port numbers are shown below, for further
information, please see IANA‟s website at:

http://www.iana.org/assignments/port-numbers