CCNA Study Guide
Introduction The Cisco Certified Network Associate (CCNA) certification is designed to
validate your knowledge and skills in networking fundamentals, network access, IP connectivity,
IP services, security fundamentals, and more. This guide provides detailed insights into each
domain to support your exam preparation.
Domain 1: Networking Fundamentals
Key Concepts
• OSI Model:
o Definition: The Open Systems Interconnection model is a conceptual framework
used to understand network interactions in seven distinct layers.
o Layers:
▪ Physical Layer (Layer 1): Deals with hardware transmission technologies
and media.
▪ Data Link Layer (Layer 2): Provides node-to-node data transfer and
error detection/correction.
▪ Network Layer (Layer 3): Manages device addressing, tracks the
location of devices, and determines the best path to send data.
▪ Transport Layer (Layer 4): Provides reliable data transfer services to the
upper layers.
▪ Session Layer (Layer 5): Manages sessions between applications.
▪ Presentation Layer (Layer 6): Translates data into a format the
application layer can accept.
▪ Application Layer (Layer 7): Provides services for network applications.
o Distinctions: Each layer performs specific functions critical for network
communication.
• TCP/IP Model:
o Definition: A suite of communication protocols used to connect network devices
on the internet.
o Layers:
▪ Network Interface: Corresponds to OSI's Physical and Data Link layers.
▪ Internet: Corresponds to OSI's Network layer. Protocols include IP.
▪ Transport: Corresponds to OSI's Transport layer. Protocols include TCP
and UDP.
▪ Application: Combines OSI’s Application, Presentation, and Session
layers.
o Distinctions: The TCP/IP model is more practical and widely used, focusing on
internet communication.
• Networking Devices:
, o Router: Forwards data packets between networks, using routing tables and
protocols.
o Switch: Connects devices within a single network, using MAC addresses to
forward data.
o Access Point (AP): Connects wireless devices to a wired network.
o Firewall: Controls access to network resources by filtering incoming and
outgoing traffic.
Practice Questions
1. What are the key differences between the OSI and TCP/IP models?
2. How do routers and switches differ in functionality?
3. Describe the primary function of a firewall in a network.
Domain 2: Network Access
Key Concepts
• Ethernet Technology:
o Definition: A family of wired networking technologies used in local area
networks (LANs).
o Standards: IEEE 802.3, with variations like Fast Ethernet, Gigabit Ethernet, and
10 Gigabit Ethernet.
o Distinctions: Ethernet technology provides high-speed data transmission, with
standards evolving to support faster speeds and greater distances.
• VLANs (Virtual Local Area Networks):
o Definition: A method to create logically segmented networks within a physical
network to improve performance and security.
o Capabilities: VLANs isolate network traffic, reduce broadcast domains, and
enhance security.
o Distinctions: VLANs allow network segmentation without physical separation,
providing flexibility and improved management.
• Wireless LAN (WLAN):
o Definition: A network that uses wireless data transmission technologies to
connect devices.
o Standards: IEEE 802.11, with variations like 802.11a/b/g/n/ac/ax.
o Distinctions: WLANs offer mobility and ease of installation but may require
additional security measures to protect against unauthorized access.
Practice Questions
1. What are the benefits of using VLANs in a network?
Introduction The Cisco Certified Network Associate (CCNA) certification is designed to
validate your knowledge and skills in networking fundamentals, network access, IP connectivity,
IP services, security fundamentals, and more. This guide provides detailed insights into each
domain to support your exam preparation.
Domain 1: Networking Fundamentals
Key Concepts
• OSI Model:
o Definition: The Open Systems Interconnection model is a conceptual framework
used to understand network interactions in seven distinct layers.
o Layers:
▪ Physical Layer (Layer 1): Deals with hardware transmission technologies
and media.
▪ Data Link Layer (Layer 2): Provides node-to-node data transfer and
error detection/correction.
▪ Network Layer (Layer 3): Manages device addressing, tracks the
location of devices, and determines the best path to send data.
▪ Transport Layer (Layer 4): Provides reliable data transfer services to the
upper layers.
▪ Session Layer (Layer 5): Manages sessions between applications.
▪ Presentation Layer (Layer 6): Translates data into a format the
application layer can accept.
▪ Application Layer (Layer 7): Provides services for network applications.
o Distinctions: Each layer performs specific functions critical for network
communication.
• TCP/IP Model:
o Definition: A suite of communication protocols used to connect network devices
on the internet.
o Layers:
▪ Network Interface: Corresponds to OSI's Physical and Data Link layers.
▪ Internet: Corresponds to OSI's Network layer. Protocols include IP.
▪ Transport: Corresponds to OSI's Transport layer. Protocols include TCP
and UDP.
▪ Application: Combines OSI’s Application, Presentation, and Session
layers.
o Distinctions: The TCP/IP model is more practical and widely used, focusing on
internet communication.
• Networking Devices:
, o Router: Forwards data packets between networks, using routing tables and
protocols.
o Switch: Connects devices within a single network, using MAC addresses to
forward data.
o Access Point (AP): Connects wireless devices to a wired network.
o Firewall: Controls access to network resources by filtering incoming and
outgoing traffic.
Practice Questions
1. What are the key differences between the OSI and TCP/IP models?
2. How do routers and switches differ in functionality?
3. Describe the primary function of a firewall in a network.
Domain 2: Network Access
Key Concepts
• Ethernet Technology:
o Definition: A family of wired networking technologies used in local area
networks (LANs).
o Standards: IEEE 802.3, with variations like Fast Ethernet, Gigabit Ethernet, and
10 Gigabit Ethernet.
o Distinctions: Ethernet technology provides high-speed data transmission, with
standards evolving to support faster speeds and greater distances.
• VLANs (Virtual Local Area Networks):
o Definition: A method to create logically segmented networks within a physical
network to improve performance and security.
o Capabilities: VLANs isolate network traffic, reduce broadcast domains, and
enhance security.
o Distinctions: VLANs allow network segmentation without physical separation,
providing flexibility and improved management.
• Wireless LAN (WLAN):
o Definition: A network that uses wireless data transmission technologies to
connect devices.
o Standards: IEEE 802.11, with variations like 802.11a/b/g/n/ac/ax.
o Distinctions: WLANs offer mobility and ease of installation but may require
additional security measures to protect against unauthorized access.
Practice Questions
1. What are the benefits of using VLANs in a network?
