A security analyst is testing both Windows and Linux systems for unauthorized DNS zone transfers within a LAN on comptia.org from example.org. Which of the following commands should the security…

nslookup is available on both Windows and Linux and can be used interactively to perform DNS zone transfers by setting the query type to AXFR and specifying the target DNS server, making it suitable for cross-platform testing as required by the scenario.

Although nslookup appears twice in the choices, choice B is a duplicate and is not independently distinct from choice A; only one instance of nslookup is needed as the correct cross-platform tool.

The 'dig -axfr [email protected]' command uses dig's AXFR (Authoritative Zone Transfer) flag to request a full zone transfer of the comptia.org zone from the DNS server at example.org, directly testing whether unauthorized zone transfers are permitted on the target server.

ipconfig /flushdns is a Windows command that clears the local DNS resolver cache and has no capability to test or perform DNS zone transfers on a remote server.

ifconfig eth0 down is a Linux command that disables a network interface entirely, which is a network configuration action and is completely unrelated to DNS zone transfer testing.

While 'dig @example.org comptia.org' queries the example.org DNS server for A records of comptia.org, it does not request an AXFR zone transfer; the missing '-axfr' flag means it performs a standard lookup rather than a zone transfer test.