Client authentication
For additional security, consider TLS with client authentication
to tightly control who can Telnet to your system over the Internet.
For example, you can configure the Telnet server to only allow authentication
if the client certificate was issued by your IBM System i (through
Digital Certificate Manager). 
The client certificates have a limited validity period (for example, 90 days). When the certificate expires, the user must perform the Client Certificate Download process in order to continue. This process requires a valid IBM System i user ID and password.
 |
Not all Telnet client software is
capable of client authentication. When enabled, all TLS-enabled Telnet
connections to the IBM System i require a user certificate. |
Refer to the IBM System i Web site
for more information.