Network Service Configuration Flashcards

A system administrator needs to configure a Linux server to act as a caching-only DNS server to speed up name resolution for local clients. Which package is most commonly installed to provide this service?

Answer: bind

BIND (Berkeley Internet Name Domain) is the most widely used software for providing DNS services on Linux. It can be configured as a caching-only server, which stores the results of DNS queries to speed up subsequent requests for the same domain names.

You are tasked with setting up a new web server. After installing the Apache HTTP Server package (httpd on RHEL/CentOS, apache2 on Debian/Ubuntu), you create a basic index.html file. Which command should you use to start the web server and ensure it automatically starts on boot?

Answer: systemctl start httpd && systemctl enable httpd

On modern Linux distributions that use systemd, 'systemctl start ' is used to start a service immediately, and 'systemctl enable ' is used to configure the service to start automatically at boot time.

A Linux server's clock is drifting significantly. To resolve this, you need to configure it to synchronize with a reliable time source on the network. Which of the following is the modern, default service used on most current Linux distributions like RHEL 8+ and recent Ubuntu versions for time synchronization?

Answer: chronyd

Chrony (chronyd) has replaced the traditional ntpd as the default Network Time Protocol (NTP) daemon on modern distributions like RHEL 8+ and recent versions of Ubuntu. It is designed to be more accurate and faster at synchronizing the system clock, especially for systems with intermittent network connections.

A system administrator needs to configure a static IP address for a server running a Debian-based distribution. Which of the following files is the primary location for configuring network interfaces on this system?

Answer: /etc/netplan/01-netcfg.yaml

Modern Ubuntu and some other Debian-based systems use Netplan as the default network management tool. Configuration is typically handled by editing a YAML file within the /etc/netplan/ directory, such as /etc/netplan/01-netcfg.yaml, to define static IP addresses, gateways, and DNS servers. While /etc/network/interfaces was used previously, Netplan is the current standard.

You are securing a vsftpd (Very Secure FTP Daemon) server and need to enforce the use of SSL/TLS for all connections, including both login and data transfer for local users. Which combination of directives in the `vsftpd.conf` file achieves this?

Answer: ssl_enable=YES force_local_logins_ssl=YES force_local_data_ssl=YES

To enforce SSL/TLS, `ssl_enable=YES` must be set to activate SSL. Then, `force_local_logins_ssl=YES` forces local users to use a secure connection to send their password, and `force_local_data_ssl=YES` ensures that the data channels for local users are also encrypted. This combination provides comprehensive encryption for user sessions.

Which of the following commands is used to display the current IP address, subnet mask, and other network interface information on a modern Linux system, replacing the older, now-obsolete `ifconfig` command?

Answer: ip addr show

The `ip` command is the modern standard for network configuration and information retrieval in Linux. The `ip addr show` (or its shorter alias `ip a`) command is specifically used to display information about network interfaces, including their IP addresses, MAC addresses, and state.