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Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wireless Networking Chapter 15 Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Objectives • Explain wireless networking standards • Describe the process for implementing Wi-Fi networks • Describe troubleshooting techniques for wireless networks Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Historical/Conceptual Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Introduction to Wireless Networking • Wireless network uses radio frequency (RF) waves to communicate between devices – Enables flexibility and mobility – Uses the same OSI layers as wired networks • Except first two OSI layers – Differs from wired networking in type of media and protocols for transmitting and accessing data – The dominant wireless implementation is Wi-Fi • IEEE 802.11 wireless Ethernet standard Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Test Specific Wi-Fi Standards Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wi-Fi Standards • Wi-Fi is by far the most widely adopted wireless networking type today • Wi-Fi technologies have been around since the late 1990s – Supported and standardized under the umbrella IEEE 802.11 standard – Examples of 802.11 amendments: 802.11g and 802.11 ac Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) 802.11 • Standards define how wireless devices communicate – Also address communication security • 802.11 established the baseline features common to all Wi-Fi standards – Wireless network cards, configuration software, capability to run in multiple network styles – How transmissions work Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Hardware • Wireless Ethernet NICs – Same function as wired, except transmission uses radio waves • Networking capabilities are built into many modern devices – Can add an expansion card to desktop computers • USB NICs are placeable Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.1 Wireless PCIe NIC Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.2 External USB wireless NIC Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wireless Access Point (WAP) • Interconnects wireless network nodes with wired networks • A basic WAP operates like a hub at Layer 1 • Often multiple devices combined in one box – Built-in switch and/or router Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.3 Linksys device that acts as wireless access point, switch, and DSL router Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Software • Wireless device drivers – Consult your vendor’s instructions • Wireless configuration utility settings – Link state – Signal strength – Wireless network modes – Security encryption – Power-saving options Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.4 Wireless client configuration utility Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wireless Network Modes • Ad hoc mode – Also called peer-to-peer mode – Uses a mesh topology – Works well for small groups of computers or temporary networks • Independent Basic Service Set (IBBS) – Two or more wireless nodes communicating in ad hoc form Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.5 Wireless ad hoc mode network Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wireless Network Modes (cont’d.) • Infrastructure mode – Uses one or more WAPs to connect the wireless network nodes centrally – Similar to a wired star topology • Basic service set (BSS) – Serviced by a single WAP • Extended service set (ESS) – Serviced by two or more WAPs Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.6 Wireless infrastructure mode network Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Range • Wireless networking range is hard to define – Greatly affected by environmental factors • Qualifiers such as around 150 feet and about 300 feet • Actual range is about half of manufacturer’s listed maximum range Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Basic Service Set Identifier (BSSID) • The most basic infrastructure mode network • A BSS of one WAP and one or more wireless clients • The BSSID is the same as the MAC address of the WAP • IBSS nodes (ad hoc mode) generate a 48-bit string as the BSSID – BSSID is added in every frame Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Service Set Identifier (SSID) • • • • Another level of naming Standard name applied to the BSS or IBSS Sometimes called a network name 32-bit identification string – In the header of each frame processed by a WAP • Every Wi-Fi device must share the same SSID to communicate in a network Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Extended Service Set Identifier (ESSID) • A Wi-Fi network with multiple WAPs (ESS) • Each WAP is connected to a central switch or switches to become part of a single broadcast domain • Clients connect to whichever WAP has the strongest signal – Roaming: process of changing WAP connections • Most Wi-Fi devices use the term SSID Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Broadcasting Frequency • Potential for interference from other wireless devices – Wireless devices must operate in specific broadcasting frequencies – A tech must know frequencies of other wireless devices in troubleshooting interference issues • Original 802.11 standards use 2.4-GHz or 5.0GHz frequencies Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Broadcasting Methods • Original IEEE 802.11 standard used spreadspectrum radio waves – Broadcasts data in small, discrete chunks – Uses different frequencies within a range Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Spread-Spectrum Broadcasting Methods • Direct-sequence spread-spectrum (DSSS) • Frequency-hopping spread-spectrum (FHSS) • Orthogonal frequency-division multiplexing (OFDM). Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Direct-Sequence Spread-Spectrum (DSSS) • • • • Sends simultaneously on different frequencies Used by early 802.11 standards Uses about 22 MHz of bandwidth Capable of greater data throughput than OFDM • More prone to interference than FHSS Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Frequency-Hopping Spread-Spectrum (FHSS) • Constantly shifts (hops) from frequency to frequency • Sends on one frequency at a time • Uses less bandwidth than DSSS (~1MHz) Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Orthogonal Frequency-Division Multiplexing (OFDM) • Latest method • Combines multiple frequencies of DSSS with FHSS’s hopping capability • Used on all but the earliest 802.11 networks Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Channels • A channel is a portion of the spectrum • 802.11 standard defined 14 channels of 20MHz each – Different countries may limit channels – In the U.S., WAP may use channels 1 through 11 • Do not use adjacent channels on nearby WAPs • Most WAPs use channels 1, 6, or 11 Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Channels (cont’d.) • The 5.0-GHz band offers many more channels than the 2.4-GHz band • There are 40 different channels in the spectrum • 802.11 versions that use the 5.0-GHz band use automatic channel switching Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) • Wireless devices cannot detect collisions – Cannot listen and send at the same time – If two clients were to collide, there is no simpleto-detect electrical peak • Two collision avoidance methods – Distributed Coordination Function (DCF) – Point Coordination Function (PCF) Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) DCF and PCF • Only DCF is implemented • DCF specifies rules for sending data onto the network media – Defines a backoff period in addition to the normal interframe gap (IFG) wait period – Requires an ACK from receiving nodes Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) 802.11b • • • • Data throughput up to 11 Mbps Range up to 300 feet Popular Uses the crowded 2.4-GHz frequency – More likely to have interference from other wireless devices – Signal interference can increase latency Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) 802.11a • Devices on market after 802.11b • Different from all other 802.11 standards – 5-GHz frequency range – Speeds up to 54 Mbps – Short range: about 150 feet – Never as popular as 802.11b – Incompatible with 802.11b Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) 802.11g • • • • • • Up to 54 Mbps Range of 802.11b: about 300 feet Backward compatible with 802.11b WAP can service both 802.11b and 802.11g All 802.11g network runs in native mode Runs in mixed mode if 802.11b devices added – Communications drop to 11 Mbps max Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) 802.11n • • • • • • • Faster and newer antenna technology Most devices must use multiple antennas Multiple in/multiple out (MIMO) Up to 600 Mbps theoretically Many WAPs employ transmit beamforming Dual-band WAPs run at 2.4- and 5.0 GHz WAPs support 802.11b/g/n devices Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) 802.11ac • • • • • • Expansion of the 802.11n standard Incorporates additional streams Wider bandwidth Better speed Only operates in the 5.0 GHz band Multiuser Mimo (MU-MIMO) – Can broadcast to multiple users simultaneously Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wi-Fi Protected Setup (WPS) • A special standard created by the wireless industry to makes configuration easier • Works in two modes – Push button – PIN method • Easy to use • Susceptible to various WPS attacks Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wi-Fi Security • Problem – Easy-to-install devices have no default security – Network data frames are in radio waves • Three wireless security methods – MAC address filtering – Authentication – Data encryption Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) MAC Address Filtering • Limits access to specific NICs • Lists MAC addresses for accepted users – The list is stored in a table in the WAP • • • • Rejects frames with other MAC addresses Alternatively create an exclusion list Not scalable on a modern network Problem: hackers can spoof MAC addresses Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wireless Authentication • • • • Users with proper credentials get access Can use a centralized security database Requires extra steps for wireless users 802.1X standard – RADIUS server – Extensible Authentication Protocol (EAP) password encryption Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wireless Authentication (cont’d.) • RADIUS server – Provides authentication for network access – Enables access to user’s rights on the network – Client wireless computer is called a supplicant – WAP is the Network Access Server (NAS) – NAS contacts the RADIUS server – RADIUS server checks the security database – User is given access if credentials are correct Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.7 Authenticating using RADIUS Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wireless Authentication Problem Areas • Connection between devices must be secure – PPP between supplicant and WAP/NAS – IPsec between NAS and RADIUS server – RADIUS server uses an authentication protocol (EAP) – WAP and wireless NICs must use the same authentication scheme Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.8 Authentication using RADIUS with protocols in place Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.9 Setting EAP authentication scheme Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Data Encryption • Encryption electronically scrambles data packets – The receiving network device requires the encryption key to unscramble the packet • WPA2 provides a good level of security to data packets in transit Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Data Encryption Using WEP • Wired Equivalent Privacy (WEP) – 64- or 128-bit encryption algorithm called RC4 – Uses an initialization vector (IV) of 24 bits • Issues with WEP – IV length uses 24 of the 64 (or 128) bits – Encryption key is static and shared – No user authentication – Outdated and easily cracked Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wi-Fi Protected Access (WPA) • Dynamic encryption key generation – Issued per user and per session • Temporal Key Integrity Protocol (TKIP) • 128-bit encryption key • Problem: key can be broken Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Wi-Fi Protected Access 2 (WPA2) • Uses Advanced Encryption Standard (AES) – 128-bit block cipher – Not completely hack proof – Difficult enough to deter casual hackers • Adding a RADIUS server for authentication enables WPA2-Enterprise Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Enterprise Wireless • Enterprise devices differ from SOHO devices – Robust construction – Centralized management – VLAN pooling – Power over Ethernet – Bringing personal wireless devices into the enterprise environment Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Robust Device Construction • Enterprise WAP is made of better materials • More configurable • Can swap out antennas and radios making it possible to upgrade to the latest technologies Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.10 Cisco Enterprise WAP Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Enterprise Wireless Administration • Large number of WAPs – Offload configuration job to a wireless controller – Switch designed to handle multiple WAPs • Thick client: configurable via its own interface • Thin clients: configurable by a wireless controller • Standard protocol: Lightweight Access Point Protocol (LWAPP) Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.11 Configuring WAPs Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.12 Wireless Controller Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) VLAN Pooling • A large number of clients may be on a single SSID at a given moment • Traditional solution – Divide the WLAN into multiple broadcast domains – Use routers to interconnect the domains • VLAN pooling – Create a pool of VLANs for a single SSID – Randomly assign wireless clients to one VLAN Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Power over Ethernet (PoE) • Power and Ethernet signals via Ethernet cables • Good for WAPs far from power outlets • The WAP and the switches must support PoE • 2003: original PoE standard 802.3af – Supported a maximum 15.4 watts of DC power – Revised in 2009 to support 25.5 watts – New amendment called 802.3at or PoE+ Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Bring Your Own Device • Integrating personal mobile devices into a corporate network • Network administrators can allow or deny mobile devices access to network resources – On- and off-boarding mobile devices • Mobile device management solutions – Provide robust security without compromising connectivity Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) WLAN vs. PAN • Wireless LAN (WLAN) – Always an 802.11-based network and able to serve multiple clients • Personal Area Networks (PAN) – Point-to-point over short distances – Examples: Bluetooth, infrared, and NFC Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Implementing Wi-Fi Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Steps for Installing a Wireless Network • Perform a site survey • Install one or more access points • Configure the access point(s) and wireless clients • Test the network to verify that it works as intended Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Performing a Site Survey • Reveals obstacles and determine best locations for access points • Main components for crating a site survey – Floor plan of the area – Wireless survey tools Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Performing a Site Survey • What wireless is already there? – Discover wireless networks in the same area – Today’s challenge is the preexistence of high device density environments – Tools are available to assist with the survey • Interference sources – Create a sketch of potential interference sources – Plan the network to eliminate dead zones Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.13 AirMagnet Survey Pro Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.14 Acrylic Wi-Fi Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.15 Site survey with heat map Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.16 Site survey with interference sources noted Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Installing the Client • Install Wi-Fi hardware and software • PCIe NIC – Install the NIC onto a free slot on the motherboard – May need to attach the antenna • USB NIC – Install drivers and software before you connect the NIC to the computer Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.17 Wi-Fi NIC installed Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Setting Up an Ad Hoc Network • Set NICs for ad hoc mode • SSID – Each wireless node must use the same network name • IP addresses – No two nodes can use the same IP address • Ensure the File and Printer Sharing service is running on all nodes Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.18 Selecting ad hoc mode in a wireless configuration utility Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Setting Up an Infrastructure Network • Determine the optimal location for the WAP • Configure the WAP • Configure any clients to access the WAP Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Placing the Access Points/Antennas • Omnidirectional antenna – Radiates outward from the WAP in all directions – Antenna is place the in the center of the area – Standard straight-wire dipole antennas are used • Omnidirectional and centered does not work for every network • The gain from a typical WAP is 2 dB – Increase gain with one or more bigger antennas Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.19 WRT54G showing two antennas Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.20 Room layout with WAP in the center Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.23 Dipole radiation pattern Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.24 Replacement antenna on a WAP Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Placing the Access Points/Antennas (cont’d.) • A unidirectional antenna focuses a radio wave into a beam – Various types: parabolic, dish, and Yagi • Patch antennas work well for a strong signal within a room • Optimal placement depends on space needs and security concerns Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Configuring the Access Point • • • • • • Log in to the browser-based setup utility Configure the SSID (ESSID) and beacon Configure MAC address filtering Configure encryption Configure channel and frequency Configure the client Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.27 Security login for Linksys WAP Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.28 Linksys WAP setup screen Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.29 Setting the beacon interval Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.30 MAC address filtering configuration screen for a Linksys WAP Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.31 Encryption key configuration screen on Linksys WAP Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.32 Encryption screen on client wireless network adapter configuration utility Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.33 Encryption screen with RADIUS option Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.34 Changing the channel Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.35 Selecting frequency Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.36 Typing in an SSID manually Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Extending the Network • Add a WAP to create an Extended Service Set • Install a wireless bridge – Connect two wireless networks; or join a wireless and a wired network together – Types of wireless bridges: point-to-point and point-to-multipoint Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.37 Linksys wireless bridge device Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Verify the Installation • Move traffic between computers using the wireless connection • Always verify installation before leaving Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Troubleshooting Wi-Fi Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Logical Troubleshooting Steps • Three types of symptoms – Cannot get on the wireless network – Wireless connections are way too slow – Wireless connection is doing weird things Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) No Connection • Channel problems – Overlapping channels – Mismatched channels • Wrong encryption – Entered the wrong encryption key – Symptoms: not on network, continual prompting for password, APIPA address – Solution: enter the correct password Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) No Connection (cont’d.) • Signal/power issues – Symptoms: signal loss, not able to connect – Solutions: • Move closer to the WAP and avoid dead spots • Turn up the power • Replace the omnidirectional antenna with a unidirectional antenna • Upgrade to newer 802.11n or 802.11ac Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.38 Increasing power on a Cisco WAP Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Slow Wireless Connections • Clear connection to an SSID • Good IP address • Potential causes of slowness – Too many devices overworking WAPs – Too much RF interference on the network – Insufficient RAM – Malware – Other non-wireless specific issues Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Overworked WAPs • Device saturation – Too many devices attaching to a single SSID over time • Bandwidth saturation • Bounce • Solutions: add extra WAPs, upgrade hardware to 802.11ac Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Interference • Sources of radio frequency interference (RFI) – Non-Wi-Fi sources including lighting, Bluetooth, wireless phones, and microwaves – Wi-Fi networks • Solution: abandon the 2.4-GHz channel • Scan for RF sources using some type of RF scanner/analyzer Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Figure 15.39 SNR on AirMagnet Copyright © 2015 by McGraw-Hill Education. All rights reserved. Mike Meyers’ CompTIA Network+® Guide to Managing and Troubleshooting Networks, Fourth Edition (Exam N10-006) Weird Connection • • • • Open (non-encrypted) 802.11 networks Wrong SSID Untested updates/incompatibilities Rogue access point (rogue AP): an unauthorized access point Copyright © 2015 by McGraw-Hill Education. All rights reserved.