nfsstat
Explanation:
The command that displays NFS kernel statistics is nfsstat. This command can be used to show information about the number and type of NFS and RPC calls made by the NFS client or server. It can also be used to reset the statistics to zero, or to display information about mounted NFS file systems. The nfsstat command is part of the nfs-utils package and can be installed on most Linux distributions. For more information about the nfsstat command, you can refer to the following resources:
1: A Microsoft Learn article that explains the syntax and usage of the nfsstat command on Windows Server.
2: A Bing search result page that shows various links and snippets related to the nfsstat command.
3: A Red Hat article that demonstrates how to use the nfsstat and nfsiostat commands to troubleshoot NFS performance issues on Linux.

Explanation/Reference: https://httpd.apache.org/docs/2.4/ssl/ssl_faq.html#aboutcerts

Explanation
To prevent anonymous FTP users from listing uploaded file names, the upload directory must not have the read or execute permission set for the anonymous user or group. The read permission allows the user to view the contents of a file or directory, while the execute permission allows the user to enter or search a directory.
Therefore, removing both permissions will prevent the user from accessing or listing the files in the upload directory. However, the write permission can be left on, as it allows the user to create or modify files in the directory, which is the purpose of an upload directory. References:
LPIC-2 Exam 202-450 Objectives, Topic 211: File Sharing, Objective 211.2: Manage FTP Service, Weight: 3 LPIC-2 Linux Professional Institute Certification Study Guide: Exam 201 and Exam 202, Chapter 9:
File Sharing, FTP, p. 353-354
Linux File Permissions Explained, Read, Write, and Execute Permissions, p. 2-4

Explanation
The option in named.conf that specifies which hosts are permitted to ask for domain name information from the server is allow-query. The allow-query option is used to define an access control list (ACL) that matches the source IP address of the DNS query. The ACL can be a list of IP addresses, networks, keywords, or predefined ACL names. The default value of allow-query is any, which means that any host can query the server. However, this can pose a security risk, as the server may be exposed to unwanted or malicious queries.
Therefore, it is recommended to restrict the allow-query option to only the hosts that need to access the server, such as the local network or trusted clients. For example, the following option allows only the hosts in the
192.168.1.0/24 network and the localhost to query the server:
allow-query { 192.168.1.0/24; localhost; };
The other options are not valid in named.conf. allowed-hosts, accept-query, permit-query, and query-group are not recognized keywords by BIND.
References:
LPIC-2 exam 202 objectives, topic 208.1, "Implementing a web server"
BIND 9 Administrator Reference Manual, chapter 6, "Access Control Lists and TSIG" How to Configure DNS Server with TSIG on CentOS 8