Chapter 19
Checking Port Status and Connectivity
Note
If you are using Kerberos to authenticate to the switch, you will not be able to use the secure shell
encryption feature.
To enable SSH 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 512 to 2048 bits. A key size with a
larger number provides higher security but takes longer to generate.
Monitoring User Sessions
You can display the currently active user sessions on the switch using the show users command. The
command output displays all active console port and Telnet sessions on the switch.
To display the active user sessions on the switch, perform this task in privileged mode:
Task
Display the currently active user sessions on the
switch.
This example shows the output of the show users command when local authentication is enabled for
console and Telnet sessions (the asterisk [*] indicates the current session):
Console> (enable) show users
Session
-------- ---------------- -------------------------
console
telnet
* telnet
Console> (enable)
This example shows the output of the show users command when TACACS+ authentication is enabled
for console and Telnet sessions:
Console> (enable) show users
Session
-------- ---------------- -------------------------
console
telnet
telnet
* telnet
Console> (enable)
78-12647-02
User
Location
sam-pc.bigcorp.com
jake-mac.bigcorp.com
User
Location
sam
jake
jake-mac.bigcorp.com
tim
tim-nt.bigcorp.com
suzy
suzy-pc.bigcorp.com
Software Configuration Guide—Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4
Command
set crypto key rsa nbits [force]
Command
show users [noalias]
Monitoring User Sessions
19-7