Quidway NetEngine20/20E
Configuration Guide - Basic Configurations
9 Telnet and SSH
Issue 05 (2010-01-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
9-3
Figure 9-2
Usage of Telnet shortcut keys
RouterA
RouterB
Telnet Server
Telnet Session 1
Telnet Session 2
RouterC
Telnet Client
Ctrl_]: The server interrupts the connection.
If the network connection is normal, when you press
Ctrl
+
]
, the
Telnet server interrupts the
current Telnet connection actively. For example:
<RouterC> (Press <Ctrl_]> to return to the prompt of RouterB.
Note: The max number of VTY users is 5, and the current number
of VTY users on line is 0.
The connection was closed by the remote host!
<RTB> (Press <Ctrl_]> to return to the prompt of RouterA.)
Note: The max number of VTY users is 5, and the current number
of VTY users on line is 0.
The connection was closed by the remote host!
<RTA>
If the network disconnects, the shortcut keys become invalid. The instruction cannot be sent to the
server.
Ctrl
_
K: The client interrupts the connection.
When the server fails and the client is unaware of the failure, the server does not respond to
the input of the client. In this case, if you press
Ctrl
+
K
, the Telnet client interrupts the
connection actively and quits the Telnet connection.
For example:
<RouterC> (Press <Ctrl_K> to directly interrupt the connection and quit Telnet
connection.
<RouterA>
9.1.3 SSH Terminal Services
Overview of SSH
When users on an insecure network log in to the router through Telnet, the Secure Shell (SSH)
feature offers security guarantee and powerful authentication. It protects the router from
attacks such as IP address spoofing and interception of plain text password.
The router can be connected with multiple SSH users.
The SSH client function allow users to establish SSH connections with a router that supports
SSH server or a UNIX host. As shown in
Figure 9-3
and
Figure 9-4
, an SSH channel is set up
for the local connection and the Wide Area Network (WAN) connection.
