Final answer:
HTTP tunneling is used to bypass firewalls, avoid intrusion detection systems, and access web servers on remote systems.
Step-by-step explanation:
HTTP tunneling is a technique used to encapsulate non-HTTP traffic within an HTTP connection. One reason to use HTTP tunneling to communicate with a remote system is to bypass a firewall. By redirecting traffic over port 80, which is typically allowed through firewalls, the non-HTTP traffic can bypass the firewall restrictions. Another reason to use HTTP tunneling is to avoid triggering an intrusion detection system. Some intrusion detection systems are configured to monitor specific ports or protocols, so by encapsulating the non-HTTP traffic within HTTP, it can go undetected. Lastly, HTTP tunneling is also used to access a web server on the remote system. Web servers typically use HTTP to communicate, so encapsulating non-HTTP traffic within HTTP allows communication with the server.