Understanding UDP

UDP is a lightweight, connectionless protocol used for data transfer. UDP does not have a handshake or connection process, nor does it have a teardown.

To see all your active UDP connections on a Windows machine, open a command line and run netstat -anp udp, as shown in the following screenshot:

Figure 9.23 – Netstat command showing UDP connection status

UDP doesn't have any ordering or reliability services; it simply delivers the data. Because of this, there isn't a need for a foreign (or remote) IP address and port. As a result, as shown in Figure 9.23, you will see only a local IP address and port for UDP.

Because of UDP's streamlined nature, it is an appropriate protocol for time-sensitive applications such as the following:

• Dynamic Host Configuration Protocol (DHCP)
• Domain Name System (DNS)
• Trivial File Transfer Protocol (TFTP)
• Voice over Internet Protocol (VoIP)

UDP is a lightweight...