A significant security issue that faces a private network from the internet is the spam mail sent from hackers to enable them to gain access to it. A spam mail is used by the hackers to a legitimate email address to lure them into opening them. Hackers use spam mails to launch malware to a network (Dodis & Stephens-Davidowitz, 2016). Such malware is embedded in such emails and becomes activated when the mail is open. Hackers then use that malware as the window to gain access to the network. A firewall is therefore used to block such emails from gaining access to a private network.
Firewalls use various protocols. The firewall protocols refer to the rules that govern the transfer of data from the source to the destination host—firewall work between the internet and a private network. Therefore, the firewalls are governed by the TCP/IP protocols (Salah et al., 2016). These protocols are used to determine how data is coded and how the firewall is configured. These protocols are typically used to establish rules that govern the regulations set by the network administrator (Cooper & Guzik, 2014). These rules are written and stored in the gateway router. These rules specify which ports are to be accessible and which IP addresses. The following are the protocols that are implemented to govern the functionality of firewalls:
The TCP protocol is a core protocol of the IP suite. This protocol provides reliable error-checking of hosts communicating over an IP network. It controls the major applications that work on the internet, such as email and file transfer. However, applications that do not need data stream service uses User Datagram Protocol (UDP) (Kenworthy, 2014). UDP provides a connectionless service to the communicating parties. TCP usually need one port to support full-duplex traffic.
Internet Assignment Numbers Authority (IANA) is another protocol that maintains official assignment of port numbers (Thomas, 2010). These protocols are designed to determine what port is open to the public or not.