SMC Networks SMC7204BRA manual Modifying Port Settings, Overview of IP port numbers

Modifying Port Settings

Modifying Port Settings

Overview of IP port numbers

The header information in an IP data packet specifies a destination port number. Routers use the port number along with the specified IP addresses to forward the packet to its intended recipient.

For example, all IP data packets that the ADSL Barricade receives from the Internet specify the same IP address (your public IP address) as the destination. However, depending on the port number contained in the data packets, the ADSL Barricade may pass the packet on to its embedded Web or Telnet servers, or to another computer on the network.

The Internet community has developed a list of common server types such as HTTP, Telnet, e-mail, and many others, and has assigned a unique port number to each. These are not mandatory, but are useful in promoting communication between separately administered LANs.

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