Using Secure Shell Encryption For Telnet Sessions - Cisco WS-C2948G-GE-TX Configuration Manual

Chapter 20 Checking Status and Connectivity
This example shows how to set the logout timer value to 10 minutes:
Console> (enable) set logout 10
Sessions will be automatically logged out after 10 minutes of idle time.
Console> (enable)
This example shows how to set the logout timer value to 0, preventing idle sessions from being
disconnected automatically:
Console> (enable) set logout 0
Sessions will not be automatically logged out.
Console> (enable)

Using Secure Shell Encryption for Telnet Sessions

To use the Secure Shell encryption commands, you must be running an encryption image.The set crypto
Note
key rsa, clear crypto key rsa, and show crypto key commands are used for encryption. See
"Working with System Software Images,"
the encryption images.
Secure Shell encryption provides security for Telnet sessions to the switch. Secure Shell encryption is
supported for remote logins to the switch only. Telnet sessions that are initiated from the switch cannot
be encrypted. To use this feature, you must install the application on the client accessing the switch and
you must configure Secure Shell encryption on the switch.
The current implementation of Secure Shell encryption supports version 1, both the data encryption
standard (DES) and 3DES encryption methods, and can be used with RADIUS and TACACS+
authentication. To support authentication for Telnet with Secure Shell encryption, enter the telnet
keyword in the set authentication commands.
If you are using Kerberos to authenticate to the switch, you will not be able to use Secure Shell
Note
encryption.
To enable Secure Shell encryption on the switch, perform this task in privileged mode:
Task
Create the RSA host key.
This example shows how to create the RSA host key:
Console> (enable) set crypto key rsa 1024
Generating RSA keys.... [OK]
Console> (enable)
The nbits value specifies the RSA key size; the valid key size range is from 512 to 2048 bits. A key size with
a larger number provides higher security but takes longer to generate.
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
Using Secure Shell Encryption for Telnet Sessions
for the software image naming conventions that are used for
Command
set crypto key rsa nbits [force]
Chapter 33,
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