netwyman

" Port Zero " does not officially exist. It is defined as an invalid port number. But valid Internet packets can be formed and sent "over the wire" to and from "port 0" just as with any other ports. Port 0 carries special significance in network programming, particularly in the Unix OS when it comes to socket programming where the port is used to request system-allocated, dynamic ports. Port 0 is a wildcard port that tells the system to find a suitable port number. Unlike most port numbers, port 0 is a reserved port in TCP/IP networking, meaning that it should not be used in TCP or UDP messages. Network ports in TCP and UDP range from number zero up to 65535. Port numbers in the range between zero and 1023 are defined as system ports or well-known ports. The Internet Assigned Numbers Authority (IANA) maintains an official listing of the intended usage of these port numbers on the internet, and system port 0 is not to be used. How TCP/UDP Port 0...

In computer networking, port forwarding or port mapping is an application of network address translation that redirects a communication request from one address and port number combination to another while the packets are traversing a network gateway, such as a router or firewall. Port Forwarding In a simple language we can say as Port forwarding or tunneling, is the behind-the-scenes process of intercepting data traffic headed for a computer's IP/port combination and redirecting it to a different IP and/or port. A program that's running on the destination computer (host) usually causes the redirection, but sometimes it can also be an intermediate hardware component, such as a router, proxy server or firewall. Even though anyone sending data to a server isn't aware of what's going on, the request will still get to its ultimate destination. Packets and the Data It all starts with the packets that get created when you send a data request over the Interne...

NAT as Network Address Translation Network Address Translation (NAT) is the process where a network device, usually a firewall, assigns a public address to a computer (or group of computers) inside a private network. The main use of NAT is to limit the number of public IP addresses an organization or company must use, for both economy and security purposes. The Purpose of NAT There are three purpose to define NAT: Provides a type of firewall by hiding internal IP addresses Enables a company to use more internal IP addresses. Since they're used internally only, there's no possibility of conflict with IP addresses used by other companies and organizations. Allows a company to combine multiple ISDN connections into a single Internet connection. NAT - Network Address Translation The Requirements of NAT - Network Address Translation Its a kind of shortage of the public IPv4 address space has forced the all of us to think harder about alternative ways of addressing net...