Telnet

See also: Software | Admin

Software to connect remotely to another system, usually a UNIX-like system. Allows a Command-Line Interface to another system for administration, E-Mail, News, FTP and other functions.

Telnet emulates a Terminal window, as if you were sitting at the remote system.

Contents

Why use Telnet?

  • Almost never crashes, unlike web browsers, E-Mail programs, and other programs.
  • Connects to a server whose dependability is often higher than your desktop computer.
  • Uses very little memory or processor to run and can be launched from very, very slow computers.
Telnet is useful for administrators to check uptime, service logs, install and run programs, etc but also may have a variety of services available for casual users:
    • FTP – usually a shell account on a remote server is faster than your home connection.
    • E-Mail – check your mail remotely, saving the time of downloading files to your home computer. For example with: Mutt or Pine.
    • WWW – surf the Web textmode with for example Links or Lynx.
    • Usenet – reading newsgroups with for example Tin.

Howto

Security

Due to the interconnected nature of the Internet, a secure solution is increasingly recommended for Telnet to prevent eavesdropping. Several protocols are available but must be supported by both the client and server.

  • SSH – has a variety of ciphers to chose from and can use public-key connections.
  • SSL – uses fewer system resources but is restricted to RC4 and 3DES ciphers. May be able to utilize public-key connections (unknown). Can also run in user space.
  • VPN and IPsec – secures all connections with a host server, including telnet, ftp, etc. but does not always confirm that individual connections are encrypted. If the server’s VPN service shuts down for any reason, users might be unaware unless non-VPN connections are not permitted.

Software

Macintosh

Note: OS X has an excellent Terminal connection system. No extra software needed.

Windows

  • By default, Telnet is available from the command prompt. In Windows 95/98/ME, type “command” and in Windows 2000/XP/2003 type “cmd” At the prompt, type “telnet servername.com”.
  • WhiteHorn Secure Terminal FREE Telnet and SSH software.
  • PuTTY – software for Telnet and SSH. MIT licensed.
  • EWAN – free telnet application

Unix

  • PuTTy is also available for Linux and Gentoo Linux. Most UNIX-like computers have a telnet client available for CLI. Just type ‘telnet’ to use it (see ‘man telnet’ for a list of options) or you can chose ‘telnet-ssl’ to use telnet over SSL, if the server supports it.

Other

Links

TakeDown.NET -> “Telnet”