PORT FORWARDING AND REDIRECTION
The majority of network services we encounter on a daily basis communicate using a client/server model. They establish a channel, negotiate options, and trade data following rules such as the Transmission Control Protocol (TCP). These TCP packets are shuffled back and forth between addresses defined by the Internet Protocol (IP), which together with TCP gives us the TCP/IP acronym. This chapter focuses on techniques for redirecting and forwarding packets across intermediate systems.
Understanding Port and Services
For a packet to reach its destination, it must have an IP address (a host on the network) ...