MicroNet SP3366, Руководство пользователя

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4.3.7 Virtual Server/ Port Forwarding
In TCP/IP 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 Authority), and these are referred to as “well-known ports”.
Servers follow the well-known port assignments so clients can locate them. If users
wish to run a server on the 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 usually needs to configure the router
to forward these incoming connection attempts using specific ports to the PC on the
network running the application. User will also need to use port forwarding if you
want to host an online game server.
The reason for this is that when using NAT, client’s publicly accessible IP address
will be used by and point to the router, which then needs to deliver all traffic to the
private IP addresses used by LAN PCs. Please see the WAN configuration section of
this manual for more information on NAT. The device can be configured as a virtual
server so that remote users accessing services such as Web or FTP services via the
public (WAN) IP address can be automatically redirected to local servers in the LAN
network. Depending on the requested service (TCP/UDP port number), the device
redirects the external service request to the appropriate server within the LAN
network.
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