CCNA 200-301 Complete Revision Guide Practice Flashcards

Comprehensive practice flashcards covering NTP, DNS, DHCP, SNMP, Syslog, SSH, NAT, QoS, Security, Architectures, Wireless, and Automation for the CCNA 200-301 exam.

Network Time Protocol (NTP)

A protocol used to synchronize the clocks of network devices to ensure consistent timestamps across logs.

Stratum 0

The original time source, typically an Atomic Clock or GPS Clock.

Stratum Hierarchy

A system where the Stratum number tells you how far a device is from the original time source; a lower number indicates higher accuracy.

NTP Port Number

UDP 123

Domain Name System (DNS)

A system that translates human-friendly names (e.g., www.google.com) into IP addresses.

Hosts File

The local file Windows checks for name resolution before querying a DNS server.

Dynamic Host Configuration Protocol (DHCP)

A protocol that automatically assigns IP addresses, subnet masks, default gateways, and DNS servers to network devices.

DHCP Port Numbers

UDP 67 for the Server and UDP 68 for the Client.

DORA Process

The four-step process for DHCP: Discover, Offer, Request, and Acknowledge.

DHCP Relay (ip helper-address)

A configuration on a router that enables it to forward DHCP broadcast requests as unicast packets to a remote DHCP server.

Simple Network Management Protocol (SNMP)

A protocol used by administrators to monitor and manage network devices through a Network Management Station (NMS).

SNMPv3

The most secure version of SNMP, adding authentication, encryption, and integrity.

Management Information Base (MIB)

A database on a managed device that stores status information such as CPU usage and interface status.

Object Identifier (OID)

A unique identifier for every piece of information stored within a MIB.

SNMP Port Numbers

UDP 161 for the SNMP Agent and UDP 162 for the SNMP Manager (Traps).

Syslog

A protocol used to record and store event log messages from network devices.

Syslog Port Number

UDP 514

Syslog Severity Level 0

Emergency: The most serious level, indicating the system is unusable.

Syslog Severity Level 7

Debugging: The least serious level, providing information for troubleshooting.

Secure Shell (SSH)

A secure, encrypted protocol used for remote device management on TCP port 22.

Telnet

An insecure, unencrypted protocol used for remote management on TCP port 23.

FTP Ports

TCP 21 for Control (commands) and TCP 20 for Data transfer.

Trivial File Transfer Protocol (TFTP)

A simple, unauthenticated file transfer protocol using UDP port 69.

RFC 1918 Private IP Ranges

10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.

Static NAT

A one-to-one mapping of a private IP address to a public IP address.

Port Address Translation (PAT)

Also called NAT Overload; it allows many private IP addresses to share one public IP address using unique port numbers.

Quality of Service (QoS)

A set of technologies used to prioritize sensitive traffic, like voice and video, over less important traffic.

DSCP 46 (EF)

The standard QoS marking for Voice traffic, representing Expedited Forwarding.

Jitter

Variation in packet delay; for voice, it should be $\\leq 30\\,ms$.

CIA Triad

The core security principles: Confidentiality, Integrity, and Availability.

AAA

Authentication (who you are), Authorization (what you can do), and Accounting (what you did).

RADIUS

An open standard AAA protocol that uses UDP ports 1812 and 1813.

TACACS+

A Cisco-proprietary AAA protocol that uses TCP port 49 and encrypts the entire packet.

DHCP Snooping

A Layer 2 security feature that prevents rogue DHCP servers by categorizing ports as Trusted or Untrusted.

Dynamic ARP Inspection (DAI)

A security feature that prevents ARP Spoofing by validating ARP packets against the DHCP Snooping Binding Table.

Cisco Three-Tier Architecture

A modular LAN design consisting of the Access, Distribution, and Core layers.

Spine-Leaf Architecture

A data center topology optimized for East-West traffic where every Leaf switch connects to every Spine switch.

MPLS (Multiprotocol Label Switching)

A WAN technology that forwards packets using labels rather than IP addresses to provide high performance and scalability.

Type 1 Hypervisor

A 'Bare Metal' hypervisor that runs directly on physical hardware, such as VMware ESXi.

IaaS (Infrastructure as a Service)

A cloud model where users rent physical or virtual servers, storage, and networking.

VRF (Virtual Routing and Forwarding)

A technology that allows a single physical router to run multiple virtual routing tables.

CSMA/CA

Carrier Sense Multiple Access with Collision Avoidance; the access method used by wireless networks (802.11).

CAPWAP

The protocol used for communication between Lightweight APs and a WLC, using UDP 5246 for Control and UDP 5247 for Data.

WPA3

The latest Wi-Fi security standard using GCMP (AES) and Simultaneous Authentication of Equals (SAE).

Data Plane

The plane responsible for forwarding packets through the device using ASICs and TCAM.

Control Plane

The plane responsible for making forwarding decisions and building tables (e.g., OSPF, routing tables).

Southbound Interface (SBI)

The interface used for communication between an SDN Controller and network devices (e.g., OpenFlow, NETCONF).

Northbound Interface (NBI)

The interface used for communication between applications and an SDN Controller, typically using REST APIs.

JSON

JavaScript Object Notation; a lightweight, human-readable data format using {} for objects and [] for arrays.

CRUD

The basic operations of a REST API: Create (POST), Read (GET), Update (PUT/PATCH), and Delete (DELETE).

Ansible

An agentless, push-model automation tool that uses YAML-based Playbooks and Python.

Configuration Drift

A phenomenon where network device configurations become inconsistent over time due to manual changes.