Level Flashcards

Each operating system has built-in tools for configuring and troubleshooting network connectivity.

Answer: Networking utilities

Networking utilities are built-in software tools found in operating systems that allow users to configure and troubleshoot network connectivity. Examples include `ping` for testing reachability, `ipconfig`/`ifconfig` for viewing network interface settings, and `tracert`/`traceroute` for mapping network paths. These utilities are indispensable for diagnosing network problems, verifying configurations, and monitoring network activity directly from the command line.

Software applications that allow remote access to command-line interfaces on network devices.

Answer: Terminal emulators

Terminal emulators are software applications that provide remote access to the command-line interface (CLI) of network devices like routers, switches, and servers. They typically use protocols such as SSH (Secure Shell) or Telnet to establish a connection. These tools enable network administrators to configure, manage, and troubleshoot devices from a remote workstation, making them essential for network operations.

A network for connecting personal devices, like Bluetooth.

Answer: PAN (Personal Area Network)

A Personal Area Network (PAN) is a computer network used for communication among various personal devices within a very short range, typically a few meters. Technologies like Bluetooth, NFC, and sometimes USB are commonly used to establish PANs. This allows devices such as smartphones, tablets, and wearable technology to exchange data and synchronize information directly with each other.

Provides virtualized computing resources over the internet.

Answer: IaaS (Infrastructure as a Service)

Infrastructure as a Service (IaaS) is a cloud computing model that provides virtualized computing resources over the internet. This includes virtual machines, storage, networks, and operating systems, which users can provision and manage themselves. IaaS offers the most control over the underlying infrastructure compared to PaaS or SaaS, allowing organizations to build and run their own applications and operating systems with high flexibility.

Host A receives a frame and discards it after determining it is corrupt. Which OSI layer checks frames for errors?

Answer: Data-link

The Data-link layer (Layer 2) of the OSI model is responsible for detecting and often correcting errors within frames as they are transmitted across a physical link. It uses mechanisms like Cyclic Redundancy Check (CRC) to ensure data integrity. If a frame is found to be corrupt upon reception, the Data-link layer will discard it, preventing damaged data from being passed up to higher layers.

No matter how it's configured, a single switch port is considered what?

Answer: A separate collision domain

In modern Ethernet networks, each individual port on a switch operates in full-duplex mode, meaning it can send and receive data simultaneously without collisions. Consequently, each switch port effectively creates its own separate collision domain. This design significantly improves network performance compared to older hub-based networks where all devices shared a single collision domain, leading to potential data collisions.

Identify which of the services below uses both TCP and UDP ports.

Answer: DNS

The Domain Name System (DNS) uniquely utilizes both TCP and UDP protocols on port 53. UDP port 53 is primarily used for fast, connectionless DNS queries, such as resolving hostnames to IP addresses. TCP port 53, on the other hand, is used for more reliable and larger data transfers, specifically for zone transfers between DNS servers and for DNSSEC (DNS Security Extensions) to ensure data integrity and authenticity.

Which of the following EXEC commands will reset LLDP traffic error counters?

Answer: clear lldp counters

The `clear lldp counters` command is used on network devices to reset the Link Layer Discovery Protocol (LLDP) traffic error counters to zero. This command is valuable for troubleshooting and monitoring, as it allows an administrator to clear previous error statistics. By resetting the counters, one can obtain fresh data to accurately assess ongoing LLDP-related issues or verify the resolution of past problems.

Which of the following options are used in standard access lists?

Answer: Source address and wildcard mask

Standard access lists (ACLs) in network devices, such as Cisco routers, filter traffic based solely on the source IP address of the packets. They use a wildcard mask in conjunction with the source IP address to define a range of IP addresses that the ACL rule should match. The wildcard mask specifies which bits of the IP address must match exactly and which bits can be ignored, providing flexibility in defining address ranges.

Which statement about NTP is true?

Answer: NTP authentication is disabled by default.

By default, Network Time Protocol (NTP) authentication is disabled on most network devices. This means that NTP clients will accept time updates from any configured NTP server without verifying its authenticity, which can pose a security risk. For enhanced security and to prevent malicious time synchronization, it is highly recommended to enable NTP authentication to ensure that time updates come from trusted sources.

Which Ethernet switching method would you use if low latency is of utmost importance?

Answer: Cut-through

Cut-through switching is an Ethernet switching method designed for extremely low latency. In this method, the switch begins forwarding a frame as soon as it reads the destination MAC address, without waiting for the entire frame to be received and checked for errors. This significantly reduces the delay in packet transmission, making it ideal for applications where every microsecond counts, such as high-frequency trading or real-time voice/video.