Question: When a Security Gateway (SEG) is removed from a telecom network, what action should the operator take regarding the SEG's certificate for security purposes?
Option 1: Immediately revoke the SEG's certificate and list it in both the Certificate Revocation List (CRL) and Online Certificate Status Protocol (OCSP) server.
Option 2: Update the SEG's certificate to reflect its new offline status but keep it active for a transitional period.
Option 3: Permanently store the SEG's certificate in an archive for future reference, without any further action.
Option 4: Automatically transfer the SEG's certificate to a backup Security Gateway.
Explanation: When a SEG is removed from the network, to maintain network security and prevent potential misuse of the SEG's credentials, the operator must ensure the SEG's certificate is invalidated. Listing the certificate in both the CRL and OCSP server ensures that all parties can verify the certificate's invalidity, enhancing network security.