RTelnet is a

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client version of

telnet Telnet is an application protocol used on the Internet or local area network to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection. User data is interspersed in-band with Telnet cont ...

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

systems. The RTelnet utility provides similar functionality of telnet to those hosts which are behind a

firewall Firewall may refer to: * Firewall (computing), a technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts * Firewall (construction), a barrier inside a building, designed to limit the spre ...

. Normally, firewalls are designed to permit or deny network transmissions based upon a set of rules. Network accessibility across the firewall is reduced in order to provide adequate security to hosts within the firewall. Because of this, many services can not directly access the resources placed outside the firewall. RTelnet utility provides functionality of

while maintaining the security requirement of firewall and

NAT Nat or NAT may refer to: Computing * Network address translation (NAT), in computer networking Organizations * National Actors Theatre, New York City, U.S. * National AIDS trust, a British charity * National Archives of Thailand * National ...

. Though the utility differs very much from its counterpart in implementation, it behaves almost indistinguishably to users in terms of command interface and communication scheme. RTelnet is a "versatile" client - it can be used for both connections to inside hosts directly and to outside hosts via SOCKS proxy servers.

Protocol details

When RTelnet starts, it prints its version number and the name or IP address of its default SOCKS proxy server to

stderr In computer programming, standard streams are interconnected input and output communication channels between a computer program and its environment when it begins execution. The three input/output (I/O) connections are called standard input (stdin ...

stream channel. It then consults the configuration file (/etc/socks.conf) to determine whether a request should be allowed or denied based on the requesting user, the destination host, and the requested service. For allowable requests, the configuration file also dictates whether direct or proxy connection should be used to the given destination, and optionally the actual SOCKS servers to use for the proxy connection. The RTelnet utility requires the libsocket.so shared library to run. RTelnet is a listed project on

SourceForge SourceForge is a web service that offers software consumers a centralized online location to control and manage open-source software projects and research business software. It provides source code repository hosting, bug tracking, mirrori ...

code repository.RTelnet project on SourceForge
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References

{{Reflist Application layer protocols Clear text protocols History of the Internet Internet protocols Internet Standards Internet Protocol based network software Remote administration software Telnet Unix network-related software