Adavanced Wireless network

1. Wireless Networks and Security
CCNA Course Overview

2. Overview of Wireless
Communication
• - Wireless communication relies on radio
waves for data transmission.
• - It differs from wired communication, which
uses physical cables.
• - Wireless networks are more flexible but also
more susceptible to interference and
eavesdropping.

3. Radio Frequency (RF)
Communication
• - RF communication uses specific frequency
bands to transmit data.
• - Common bands include 2.4 GHz, 5 GHz, and
newer 6 GHz bands.
• - RF signals propagate through the air, and
their quality can degrade due to distance,
obstacles, and interference.

4. Types of Wireless Networks: WLAN
• - WLAN (Wireless Local Area Network) is used
in homes, businesses, and public places.
• - Uses IEEE 802.11 standards.
• - Typically ranges from 30 to 100 meters.

5. Types of Wireless Networks: WPAN
• - WPAN (Wireless Personal Area Network) is
used for short-range communication.
• - Examples include Bluetooth and Zigbee
technologies.
• - Range is typically up to 100 meters.

6. Types of Wireless Networks:
WWAN
• - WWAN (Wireless Wide Area Network)
connects geographically dispersed locations.
• - Includes 3G, 4G, and 5G technologies.
• - Used for mobile data communication over
large areas.

7. Wireless Standards: IEEE 802.11a
• - 802.11a operates on the 5 GHz band.
• - Maximum data rate of 54 Mbps.
• - Shorter range compared to 2.4 GHz
standards.

8. Wireless Standards: IEEE 802.11b/g
• - 802.11b operates on the 2.4 GHz band with a
maximum rate of 11 Mbps.
• - 802.11g also operates on the 2.4 GHz band,
but with 54 Mbps max speed.
• - 802.11g is backward compatible with
802.11b.

9. Wireless Standards: IEEE
802.11n/ac
• - 802.11n operates on both 2.4 GHz and 5 GHz
bands, with a maximum speed of 600 Mbps.
• - 802.11ac operates on 5 GHz, offering speeds
up to 3.5 Gbps (with MU-MIMO).

10. Wireless Standards: IEEE 802.11ax
(Wi-Fi 6)
• - Wi-Fi 6 (802.11ax) provides higher speeds
and better efficiency in congested
environments.
• - It operates on 2.4 GHz and 5 GHz bands and
supports up to 9.6 Gbps.
• - Features like OFDMA and MU-MIMO
enhance network capacity.

11. RF Spectrum and Radio Waves:
Frequency Bands
• - Wireless devices operate in specific
frequency bands, such as 2.4 GHz, 5 GHz, and
6 GHz.
• - 2.4 GHz has a wider range but is more prone
to interference.
• - 5 GHz offers faster speeds but shorter range.

12. RF Spectrum and Radio Waves:
Propagation & Interference
• - Wireless signals degrade over distance and
can be affected by obstacles (e.g., walls,
furniture).
• - Interference from other devices (e.g.,
microwaves, cordless phones) can reduce
signal quality.

13. Wireless Security Threats:
Eavesdropping
• - Eavesdropping occurs when an attacker
intercepts wireless data transmissions.
• - Tools like Wireshark can capture and analyze
wireless traffic.
• - Encryption (WPA2/WPA3) mitigates this
threat.

14. Wireless Security Threats: MITM
Attacks
• - MITM (Man-in-the-Middle) attacks involve
intercepting and possibly altering
communications.
• - Attackers can use rogue APs or other
methods to position themselves between the
victim and the network.

15. Wireless Security Threats: Rogue
Access Points
• - Rogue APs are unauthorized devices that
mimic legitimate access points.
• - They can trick users into connecting, allowing
attackers to steal data or launch further
attacks.

16. Wireless Security Threats: Jamming
• - Jamming occurs when attackers deliberately
interfere with wireless signals.
• - Can disrupt communication, causing devices
to lose connection or degrade network
performance.

17. WPA, WPA2, WPA3: WEP
• - WEP (Wired Equivalent Privacy) is an
outdated and insecure protocol.
• - Vulnerable to attacks like packet sniffing and
key cracking.
• - Not recommended for modern networks.

18. WPA, WPA2, WPA3: WPA
• - WPA (Wi-Fi Protected Access) improved on
WEP by using TKIP encryption.
• - While better than WEP, it is still considered
less secure compared to WPA2.

19. WPA, WPA2, WPA3: WPA2
• - WPA2 uses AES (Advanced Encryption
Standard), offering stronger security.
• - WPA2 is widely used and provides robust
protection for modern wireless networks.

20. WPA, WPA2, WPA3: WPA3
• - WPA3 is the latest security protocol with
enhanced encryption methods.
• - It offers improved protection against offline
dictionary attacks and stronger public network
security.

21. Authentication and Encryption:
EAP Methods
• - EAP (Extensible Authentication Protocol)
supports various authentication methods:
• - EAP-TLS (Transport Layer Security):
Certificate-based, highly secure.
• - EAP-PEAP (Protected EAP): Encapsulates
EAP in a secure tunnel.
• - EAP-FAST: A faster authentication method
using a protected access credential.

22. Authentication and Encryption:
AES vs TKIP
• - AES (Advanced Encryption Standard)
provides strong encryption for wireless
networks.
• - TKIP (Temporal Key Integrity Protocol) is an
older encryption method, less secure than
AES.
• - WPA2 uses AES, which is more secure than
TKIP.

23. MAC Filtering and SSID Hiding:
MAC Filtering
• - MAC Filtering restricts access to wireless
networks based on MAC addresses.
• - While not foolproof, it adds an additional
layer of security by allowing only specific
devices to connect.

24. MAC Filtering and SSID Hiding:
SSID Hiding
• - Hiding the SSID prevents the network from
being broadcast to other devices.
• - While this can improve security, it is not a
complete solution and can be bypassed by
determined attackers.

25. Configuring Wireless Routers and
Access Points: SSID Configuration
• - Configuring SSID involves assigning a
network name and setting up the network’s
broadcast settings.
• - Best practices include using a unique SSID
and avoiding default names.

26. Configuring Wireless Routers and
Access Points: Wireless Modes
• - Set the wireless mode (e.g.,
802.11b/g/n/ac/ax) depending on the
network requirements.
• - Consider compatibility with client devices
when selecting a mode.

27. Configuring Wireless Routers and
Access Points: Security Settings
• - Ensure WPA2 or WPA3 encryption is enabled.
• - Set a strong password for the network,
avoiding default or weak passwords.

28. Configuring Wireless Routers and
Access Points: Channel Selection
• - Choose wireless channels that are least
congested to minimize interference.
• - Use tools like Wi-Fi analyzers to find optimal
channels for your network.

29. Configuring Wireless Clients:
Connecting Devices
• - Devices can connect to the wireless network
using the SSID and passphrase.
• - Troubleshoot common issues like weak
signals or incorrect network credentials.

30. Advanced Wireless Features:
Roaming and Handover
• - Roaming allows wireless clients to seamlessly
switch between APs without losing
connection.
• - This is essential for maintaining continuous
network access in large areas.

31. Advanced Wireless Features: Mesh
Networks
• - Mesh networks extend the coverage of
wireless networks by using multiple
interconnected APs.
• - Mesh networks help cover large areas
without requiring additional wired
infrastructure.

32. Conclusion
• - Wireless networks are essential for flexible
and mobile connectivity.
• - Proper security and configuration ensure
reliable and safe operation.
• - Understanding wireless principles, security,
and configuration is critical for managing
modern networks.

33. RF Spectrum: Propagation and
Interference
• - RF signals propagate through the air, and
their quality is affected by distance, obstacles
(walls, furniture), and interference.
• - The environment can cause signal
degradation, resulting in slower speeds or
dropped connections.
• - **Interference:** Devices like microwaves,
cordless phones, and other Wi-Fi networks
can interfere with your RF signals.

34. RF Spectrum: Frequency Bands (2.4
GHz, 5 GHz)
• - **2.4 GHz Band:** Offers longer range but is
more crowded, with more potential for
interference.
• - Maximum speed: Up to 600 Mbps (Wi-Fi 4).
• - 14 channels, but many overlap.
• - **5 GHz Band:** Faster speeds and less
interference, but with shorter range.
• - Maximum speed: Up to 3.5 Gbps (Wi-Fi
5/6).

35. SSID: Definition and Role
• - **SSID (Service Set Identifier):** The name
of a wireless network that identifies a specific
access point.
• - Devices use SSID to join a specific network
within the coverage area.
• - Default SSID names should be changed to
prevent confusion and ensure security.

36. SSID: Configuring and Hiding SSID
• - **Configuring SSID:** Choose a unique
name for your wireless network to avoid
confusion.
• - Use a name that doesn’t reveal the location
or purpose of the network.
• - Avoid using default SSID names (e.g.,
Linksys, Netgear).
• - **Hiding SSID:** Hiding the SSID makes the
network invisible to most devices.

37. Non-overlapping Wi-Fi Channels:
2.4 GHz
• - The 2.4 GHz band has 14 channels, but only 3
non-overlapping channels: **1, 6, 11**.
• - Overlapping channels lead to interference,
reducing network performance.
• - **Best Practice:** Choose one of these non-
overlapping channels to minimize
interference.

38. Non-overlapping Wi-Fi Channels: 5
GHz
• - The 5 GHz band has more channels and less
interference than the 2.4 GHz band.
• - 5 GHz offers 23 non-overlapping channels,
making it ideal for high-density networks.
• - **Best Practice:** Select channels 36, 40,
44, 48, 149, 153, 157, 161 for better
performance.

39. Access Points: Types of Access
Points
• - **Standalone Access Points:** Self-
contained devices that provide wireless access
to a network.
• - Simple and easy to set up, suitable for small
environments.
• - **Controller-based Access Points:**
Connected to a centralized controller for
management.
• - Scalable for larger networks and offer

40. Access Points: Role in Networks
• - **Central Connection Hub:** Access points
act as bridges between wired and wireless
networks.
• - **Signal Distribution:** Distribute the
wireless signal across the network to
connected devices.
• - **Network Expansion:** APs can be added
to extend the coverage area of a wireless
network.

41. Access Points: Placement and
Performance
• - **Placement:** The location of an AP affects
signal strength, coverage, and performance.
• - Avoid placing APs near large metal objects
or thick walls.
• - **Channel Allocation:** APs should be
placed on different channels (especially in the
2.4 GHz band) to avoid interference.

42. Access Points: Advanced Features
(PoE, Mesh)
• - **Power over Ethernet (PoE):** Allows APs
to be powered via Ethernet cables, eliminating
the need for additional power sources.
• - **Mesh Networking:** APs can be
connected in a mesh topology to extend
network coverage across larger areas.

43. CSMA/CA: Overview
• - **CSMA/CA (Carrier Sense Multiple Access
with Collision Avoidance):** A protocol used
by wireless networks (e.g., Wi-Fi).
• - In CSMA/CA, devices "listen" to the channel
to check if it is clear before transmitting data.
• - If the channel is busy, the device waits until it
becomes idle.
• - **Purpose:** Avoids collisions in a shared
medium by listening before sending.

44. CSMA/CA: How it Works
• - **Listen:** The device checks if the medium
is idle.
• - **Wait for Idle:** If the medium is busy, the
device waits for a random period.
• - **Transmission:** Once the channel is clear,
the device sends data.
• - **ACK (Acknowledgment):** After
transmission, the sender waits for an
acknowledgment to ensure the data was

45. CSMA/CD: Overview
• - **CSMA/CD (Carrier Sense Multiple Access
with Collision Detection):** A protocol used
by wired Ethernet networks.
• - In CSMA/CD, devices listen to the channel
and transmit data when it's idle.
• - If two devices transmit at the same time, a
collision occurs. Devices then stop
transmitting, wait for a random time, and
retransmit.

46. CSMA/CD: How it Works
• - **Listen:** The device listens for a clear
channel before sending data.
• - **Transmit:** If the channel is idle, data is
transmitted.
• - **Collision Detection:** If another device
transmits at the same time, a collision is
detected.
• - **Backoff and Retransmit:** After a collision,
both devices stop, wait for a random time, and