The showmount utility relies on which protocol family to query NFS exports?

The showmount utility relies on which protocol family to query NFS exports?

• A. DNS
• B. SMTP
• C. HTTP
• D. RPC

Answer: (D)

The concept being tested is that NFS communication relies on the RPC family, and showmount uses that same protocol to discover exports. NFS is built on ONC RPC, and the mountd service that provides the list of exported directories speaks RPC. When you run showmount, it reaches the server’s portmapper/rpcbind service to locate the mountd daemon and then issues an RPC call to retrieve the exported file systems. That’s why RPC is the correct choice. DNS, SMTP, and HTTP serve entirely different functions (name resolution, mail, and web traffic, respectively) and aren’t used to query NFS exports, which is why they don’t fit here.

The concept being tested is that NFS communication relies on the RPC family, and showmount uses that same protocol to discover exports. NFS is built on ONC RPC, and the mountd service that provides the list of exported directories speaks RPC. When you run showmount, it reaches the server’s portmapper/rpcbind service to locate the mountd daemon and then issues an RPC call to retrieve the exported file systems. That’s why RPC is the correct choice.

DNS, SMTP, and HTTP serve entirely different functions (name resolution, mail, and web traffic, respectively) and aren’t used to query NFS exports, which is why they don’t fit here.