Linux+ Networking Services and Protocols Flashcards

Which protocol automatically assigns IP addresses, subnet masks, and default gateways to network clients?

Answer: DHCP

DHCP (Dynamic Host Configuration Protocol) dynamically leases IP configuration parameters to network clients.

Which file contains static hostname-to-IP address mappings that are checked before DNS?

Answer: /etc/hosts

/etc/hosts contains static hostname-to-IP mappings; by default nsswitch.conf checks this file before querying DNS.

What is the primary purpose of NTP (Network Time Protocol) in a Linux environment?

Answer: Synchronize system clocks across the network

NTP synchronizes the system clock to a reliable time source, ensuring accurate and consistent timestamps across all systems.

Which modern command replaces netstat and displays active network connections and listening ports?

Answer: ss

ss (socket statistics) is the modern replacement for netstat and displays TCP/UDP connections, listening sockets, and socket states.

Which service is a modern NTP implementation that synchronizes the Linux system clock with remote time servers?

Answer: chronyd

chronyd is a modern, more accurate NTP implementation that adjusts and maintains system clock synchronization with remote NTP servers.

Which command is the 'Swiss Army knife' of networking, capable of testing TCP/UDP port connectivity?

Answer: nc

nc (netcat) can open TCP/UDP connections to any host and port, making it useful for testing whether services are listening.

What does the command `ssh-keygen -t ed25519` do?

Answer: Generates an Ed25519 SSH key pair

ssh-keygen -t ed25519 generates a new Ed25519 key pair, which is more secure and compact than RSA keys.