Configuring the telnet server, Introduction, Telnet fundamentals – RuggedCom RuggedRouter RX1100 User Manual
Page 266: Telnet server configuration, 266 31.2. telnet fundamentals, 266 31.3. telnet server configuration, Telnet server configuration main menu
31. Configuring The Telnet Server
Revision 1.14.3
266
RX1000/RX1100™
31. Configuring The Telnet Server
31.1. Introduction
This chapter familiarizes the user with configuration of the Telnet server.
31.2. Telnet Fundamentals
Telnet is an IP network protocol (RFC854) that provides remote terminal access to a system on TCP
port 23. Telnet is commonly used to refer to both the protocol and to the server and client programs
that implement it.
An important consideration when using telnet is that both the authentication process and the entire
session are transmitted in the clear, i.e. unencrypted. This makes it possible for an attacker to log the
telnet session as it appears on the network, and acquire from it the username and password of the
account used to log in via telnet, along with the entire text of a login session.
Note
Wherever possible, the use of SSH is recommended over telnet, since SSH encrypts both the
authentication exchange and the session. For information on the configuring the SSH server on
RuggedRouter please refer to
There are some situations in which remote network access to the router is necessary and an SSH
client is not readily available, but a telnet client is. Older computer systems or network terminal
devices, for example, may support telnet and not SSH, due in part to the fact that telnet itself has
been in use for several decades and that it requires much fewer resources than does SSH.
One way to decrease the risk associated with running a telnet server on RuggedRouter is to configure
the firewall to restrict telnet connections. It would be advisable, for example, to allow telnet connections
only from the LAN side of the router, and prevent them from the WAN side.
31.3. Telnet Server Configuration
Figure 31.1. Telnet Server Configuration Main Menu
The Listen on address field and list are used to control which local router addresses the telnet server
will respond from. If "All addresses" is selected, then the router's telnet server will be reachable via