Which protocol is commonly employed for secure remote access to networks through firewalls?

The use of Secure Socket Layer (SSL) for secure remote access to networks through firewalls is foundational in ensuring encrypted communications over networks. SSL provides a framework that allows secure connections to be established, safeguarding the data being transmitted against eavesdropping and tampering. This is critical, especially when accessing sensitive information across firewalls, as it protects against potential threats that can exploit unsecured connections.

SSL encrypts the data at the transport layer, ensuring that it remains confidential between the client and the server. Many applications and protocols, such as HTTPS (which is HTTP over SSL), utilize SSL/TLS to secure web traffic. In the context of firewalls, SSL is extensively used to create secure tunnels that allow remote users to access internal resources safely, thereby providing a robust mechanism for securing remote access in various use cases.

In contrast, protocols like FTP and HTTP do not natively include encryption, making them less suitable for secure remote access. ICMP is primarily used for network diagnostics and is not designed for secure communication. Thus, SSL stands out as the appropriate choice for establishing secure remote access to networks through firewalls.