A legacy system is not scheduled to be decommissioned for two years and requires the use of the standard Telnet protocol. Which of the following should be used to mitigate the security risks of this…

Migrating to IPv6 changes the network layer protocol but does nothing to address Telnet's unencrypted transmission of credentials and session data.

RSH (Remote Shell) is also a cleartext, unauthenticated protocol and provides no security improvement over Telnet.

Moving the system to a secure VLAN creates logical network segmentation that restricts which endpoints can initiate a Telnet session, reducing the attack surface without requiring any changes to the legacy system. This compensating control contains potential compromise to the isolated segment rather than exposing the plaintext protocol to the broader network.

LDAPs secures directory service authentication traffic but does not encrypt or protect the Telnet session itself, which remains transmitted in plaintext.