Fast Fixes to Wi-Fi Problems

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{{Welcome}} {{GoogleSearch}} {{Contributions}} {{Donate}} '''This articles covers fast fixes to common Wi-Fi problems.''' {{Wi-Fi Articles}} __FORCETOC__ == Top Ten Fixes to Wi-Fi Problems == {| | || align="right" | 10. || || Upgrade Wi-Fi products to latest firmware. |- | || align="right" | 9. || || Try older firmware in Wi-Fi products. |- | || align="right" | 8. || || Reinstall all drivers. |- | || align="right" | 7. || || Get bigger/better antenna(s). |- | || align="right" | 6. || || Replace 2.4 GHz cordless phones with 900 MHz or 5 GHz phones. |- | || align="right" | 5. || || Don't use microwave oven & Wi-Fi at the same time. |- | || align="right" | 4. || || If there's a municipal wireless network, give up now. |- | || align="right" | 3. || || Reinstall Windows. |- | || align="right" | 2. || || Throw out everything and start over with new stuff. |- | || align="right" | 1. || || Good, fast, cheap. Pick (at most) two. |} Now on to the serious stuff ... == Wireless Access Point is more expensive than Wireless Router == * See ''[[Wi-Fi How To#Use a wireless router as a wireless access point|How To Use a wireless router as a wireless access point]]'' == Don't do Double NAT == [[Image:AddWireless.png|thumb|right|Wireless Router?<br>Wireless Access Point?]] When adding wireless access to a wired network, as in the diagram at the right, be careful not to create ''double ''[[wikipedia:Network address translation|NAT]] problems. Since the wired router already has NAT, use either: * a wireless access point (with no NAT) instead of a wireless router (with NAT), or * [[Wi-Fi How To#Use a wireless router as a wireless access point|a wireless router setup as a wireless access point]]. See also "Configure a Network with Multiple Routers" in ''[http://www.microsoft.com/windowsxp/using/networking/expert/russel_05Feb.mspx Answering Some Common Windows XP Home Networking Questions]'' == Can't connect to Wi-Fi client bridge and Internet at the same time == In network terms, a ''[[Wikipedia:Network bridge|bridge]]'' is transparent, passing data from each side to the other side (wireless to wired, wired to wireless). Thus in normal operation it doesn't have any use for [[wikipedia:IP address|IP addresses]], just [[wikipedia:Media Access Control|MAC addresses]]. However, because of the need to ''manage'' Wi-Fi operation ([[wikipedia:Service set identifier|SSID]] selection, [[wikipedia:Wired Equivalent Privacy|WEP]]/[[wikipedia:Wi-Fi Protected Access|WPA/WPA2]] security, ''etc.''), a Wi-Fi client bridge will typically have ''configuration screen(s)'' at a specified [[wikipedia:Private network|private IP address]] (''e.g., ''192.168.0.254) that can be accessed with a standard Web browser (''e.g., ''Microsoft Internet Explorer) from a local computer. Unfortunately, unlike with a Wi-Fi router, a computer connected to a Wi-Fi client bridge ''can't'' normally communicate with both the client bridge configuration and the Internet at the same time. To deal with this problem, see [[Wi-Fi How To#Configure a Wi-Fi client bridge|How To Configure a Wi-Fi client bridge]]. == Poor coverage or range (weak signal) == === Reduce possible interference === * See ''[[#Too much wireless (RF) interference|Too much wireless (RF) interference]]'' === Better antenna (which helps both sending and receiving) === * Do It Yourself ** See ''[[Wi-Fi How To#Make a Wi-Fi antenna or reflector for cheap|How To Make a Wi-Fi antenna or reflector for cheap]]'' *** ''Really works!'' *** Can help even when antenna isn't replaceable * Commercial replacement antenna (some, but not all, products have ''replaceable antennas'') ** See ''[[Wi-Fi#Antennas|Wi-Fi Antennas]]'' Amount of antenna improvement * Standard "rubber duck" [[wikipedia:Antenna gain|antenna gain]] (effectiveness) is about 2 dBi. * It takes an ''increase of 6 dB to double range''. Thus: :{| border="1" | align="right" | &nbsp;Antenna: | &nbsp;&nbsp;&nbsp;&nbsp;2 dBi&nbsp; | &nbsp;&nbsp;&nbsp;&nbsp;8 dBi&nbsp; | &nbsp;&nbsp;14 dBi&nbsp; | &nbsp;&nbsp;''etc.''&nbsp;&nbsp; |- | align="right" | &nbsp;Range: | align="center" | 1x | align="center" | 2x | align="center" | 4x | align="center" | ''...'' |} === "High gain" Wi-Fi adapter === * [http://www.hawkingtech.com/products/productlist.php?CatID=32&FamID=60&ProdID=280 Hawking HWU8DD Hi-Gain USB Wireless-G Dish Adapter] === Increase transmit power === * Won't help on ''receiving'', so higher power may well be needed at ''both ends''. * Takes a ''lot'' more power to make a substantial difference in range. * May increase ''interference'' to other users of the frequency band. * Improving antenna (helping sending & receiving) is usually ''more effective & neighborly''. === Add additional wireless Access Point(s) === * See ''[[Wi-Fi How To#Add additional Wi-Fi access points (to increase coverage)|How To Add additional Wi-Fi access points (to increase coverage)]]'' === Switch to [[wikipedia:Multiple-input multiple-output communications|MIMO]] products === * Greatly increased range/speed over standard Wi-Fi * Must be ''same kind of MIMO at both ends'' to get any benefit * Current MIMO products are ''proprietary'', may ''not'' be compatible with eventual [[wikipedia:IEEE 802.11#802.11n|802.11n]] standard == Wireless connection drops periodically == * Possible '''interference''' -- see ''[[#Too much wireless (RF) interference|Too much wireless (RF) interference]]'' * '''Weak signal''' -- weaker than you think -- see [[#Don't trust Windows signal strength or speed]] * Try ''manufacturer's wireless connection manager'' -- If your hardware came with its own ''wireless connection manager'', trying installing and configuring it to manage wireless connections. (Some drivers will not maintain the association with the strongest signal access point in situations with high density access points.) === Don't trust Windows signal strength or speed === Even when signal is weak, Windows may report a good signal upon initial connection: [[Image:Windows signal strength 1.png|center]] A bit later, more accurate signal is reported, but Windows is still reporting full 802.11g speed: [[Image:Windows signal strength 2.png|center]] In this case the signal was so weak the connection would not work, and was soon lost. The problem isn't Windows itself, but the wireless device driver from the wireless vendor -- Windows is just reporting what the driver tells it. In addition, this doesn't tell you anything at all about signal ''quality'' and the amount of ''[[#Too much wireless (RF) interference|interference]]'', which are as important as signal ''strength''. '''Moral:''' Don't trust signal strength or speed as reported by Windows. You may (or may not) get more accurate information from the wireless manufacturer's connection manager, or a tool like [http://www.netstumbler.com/ Network Stumbler (NetStumbler)] instead. === May not actually be Connected === {| style=width="100%" |[[Image:Windows Status Connected.png|thumb]] |&nbsp;&nbsp;&nbsp; |Windows may show Wi-Fi<br>as being connected ...<br>&larr; <p align="right">... when it doesn't actually<br>have a working connection<br>as shown in<br>Connection Status<br>&rarr;</p> |[[Image:Wi-Fi not really Connected.png|thumb]] |} [[Image:Windows wireless set to No Notify.png|thumb|Windows wireless set to No Notify]] Possible causes: * DHCP failure (interference and/or weak signal, broken DHCP server, or problem with Windows Vista DHCP client). * Initial connection with wrong WEP/WPA/WPA2 key, and is waiting to complete the connect. * Wireless connection has been lost due to interference and/or weak signal, and is waiting to reconnect. You may not easily know about this kind of problem if Windows isn't configured to notify you. '''Checking "Notify me when this connection has limited or no connectivity" is recommended.''' To establish working connectivity, you can: # Wait until Windows re-establishes the connection automatically. # Click the Repair button to try to fix the connection more quickly. # Find and correct the cause of the problem (e.g., wrong WEP/WPA/WPA2 key, DHCP failure, insufficient signal). === Android device connection problems === Certain [[wikipedia:Android (operating system)|Android]] mobile devices ([[wikipedia:Mobile phone|mobile phones]], [[wikipedia:Tablet computer|tablets]]) may connect to Wi-Fi and work for a time but then "hang" or disconnect. The cause appears to be a bug in certain [[wikipedia:Texas Instruments|TI]] Wi-Fi drivers most commonly used in certain [[wikipedia:Motorola Mobility|Motorola]] products. The best solution may be to replace the Android device with a completely different device, if possible, that works properly everywhere. Otherwise, a possible work-around (where you control the wireless access point or wireless router, but not in other places) is to either: <ol style="list-style-type: lower-alpha;"> <li>disable [[wikipedia:Wireless Multimedia Extensions|WMM or WME (Wireless Multimedia Extensions)]] in the wireless access point or wireless router (not the mobile device), at the expense of WMM/WME functionality; or</li> <li>replace the wireless access point or wireless router with a completely different device that's more tolerant of mobile device issues.</li> </ol> == Slow wireless speed == * So you've got a new 54 Mbps wireless network; you've [[Wi-Fi How To#Measure wireless network performance|measured actual speed]] of data transfer; and it's nowhere near 54 Mbps, even with a strong signal? You've just learned the 1st [http://www.tomsnetworking.com/2006/02/27/wireless_networking_ntk_2006/index.html Rule of Wireless Networking]: "It never goes as fast as they say it does." The reason is that wireless data can only flow on ''one'' wireless link in ''one'' direction at any one time, which means that the ''maximum data transfer rate will be well below half of the raw wireless network speed''. * The raw speed reported by your wireless adapter may ''not'' be meaningful -- see ''[[Wi-Fi#Wi-Fi Speed|Wi-Fi Speed]]''. * All that said, you may be suffering from ''[[#Poor coverage or range (weak signal)|weak signal and/or interference]]''. == Too much wireless (RF) interference == See: * [[Wi-Fi#Interference|Checklist of possible interference sources]] * [[Wi-Fi How To#Why and How to do a Site Survey|Why and How to do a Site Survey]] '''Steps:''' # Switch to a ''different channel'' ## First try ''[[Wi-Fi#Wi-Fi Channels|minimally interfering channels]]'': 1, 6, and 11 ## If that doesn't solve the problem, try other channels # Remove interference (''e.g.,'' replace 2.4 GHz cordless phone with 900 MHz or 5 GHz cordless phone) # Use a ''[[wikipedia:Directional antenna|directional antenna]]'' or ''[http://www.freeantennas.com/ reflector]'' pointed #* ''toward'' desired radio, and #* ''away from'' source of interference # Switch to [[wikipedia:IEEE 802.11#802.11a|802.11'''''a''''']] (5 GHz) == Can't connect to the Internet == Check: # [[#Can't connect to wireless router or access point|Can't connect to wireless router or access point]] # [[#Internet isn't working|Internet isn't working]] == Can't connect to wireless router or access point == ''First check [[#May not actually be Connected|May not actually be Connected]]'' # Most such ''wireless host'' devices have a web page that can be accessed with a standard web browser (''e.g., ''Internet Explorer). Check the ''user manual'' for the address of the web page, and try to connect with a web browser. # If that doesn't work, try to [[Wikipedia:ping|ping]] the wireless host; under Microsoft Windows, click ''Start'' &rarr; ''Run'',<br>type "%COMSPEC% /k ping ''WIRELESSHOSTADDRESS''" and press ''[Enter]''. # If that doesn't work, check network addresses with ''Start'' &rarr; ''Run'',<br>type "%COMSPEC% /k ipconfig /all" and press ''[Enter]''. #* The wireless adapter network address will normally begin with the same three number groups as the wireless host web page; ''e.g., ''if the wireless host web page is ''192.168.1.<u>254</u>'', then the wireless adapter should be something like ''192.168.1.<u>11</u>''. #* If you have a wireless router (not an access point), the ''Default Gateway'' should normally be the same network address as the wireless host web page. #* If the wireless adapter network address begins with ''169.254...'' then automatic address assignment has failed, and Windows has assigned a private address that ''won't work''! For troubleshooting you'll probably need to manually configure the network address. # If all else fails, you may need to reset the wireless host to ''factory default settings'', and start over. Check the ''user manual'' for how to do this. : '''For more detailed help with Windows XP, see ''[http://support.microsoft.com/default.aspx?scid=kb;en-us;314067 How to troubleshoot TCP/IP connectivity with Windows XP]''.''' == Internet isn't working == {{TODO}} == DHCP isn't working == * '''Windows''': To troubleshoot the problem, try the [[FixDHCP script]]. == Getting Windows Remote Desktop to work == * See "Use Remote Desktop for Computers Behind Routers" in ''[http://www.microsoft.com/windowsxp/using/networking/expert/russel_05Feb.mspx Answering Some Common Windows XP Home Networking Questions]'' == Accidentally connecting to neighbor's Wi-Fi == {{Tip|tiptext=Products with the ''same'' (default) SSID seem like a ''single'' network!<br>See ''[[Wi-Fi#SSID Conflict|SSID Conflict]]''}} * Set a ''unique [[wikipedia:Service set identifier|SSID]]'' in your wireless router or access point. * Set up ''security'' ([[wikipedia:Wired Equivalent Privacy|WEP]], or better yet [[wikipedia:Wi-Fi Protected Access#WPA2|WPA2]]), a ''very good idea'' in any event. == Works with no security, but won't work with WEP == * Use a ''[[wikipedia:hexadecimal|hex]]'' key, not a character (ASCII) key. See ''[[Wi-Fi#WEP|Wi-Fi WEP]]''. {{Tip|tiptext=[[wikipedia:Wired Equivalent Privacy|WEP]] can be easily cracked! If possible, use [[wikipedia:Wi-Fi Protected Access#WPA2|WPA2]] instead. See ''[[Wi-Fi#Wi-Fi_Security|Wi-Fi Security]]''.}} == Wake On LAN (WOL) won't work from the Internet == * For information on Wake On LAN, see: ** [http://www.camden411.com/tcpipfaq/wol.html Wake On LAN - An Overview] ** [[Wikipedia:Wake on LAN]] * The problem is that for a router to send magic WOL packets to your network, you need either: ** an external router interface for generating and sending magic WOL packets, or ** manual enabling of a ''static route'' or ''directed broadcast''. Many (most?) low-end routers don't have that capability because of the risk of [[wikipedia:Smurf attack|smurf denial of service attacks]]. * Wireless routers with explicit Wake-on-LAN capability ** [http://www.buffalotech.com/products/product-detail.php?productid=88 Buffalo AirStation 125 High-Speed Mode Wireless Secure Remote Gateway] * Software to generate magic WOL packets ** [http://www.1e.com/SoftwareProducts/SMSWakeUp/Index.aspx SMSWakeUp] ** [http://www.depicus.com/wake-on-lan/wake-on-lan-gui.aspx Wake on Lan for Windows] == Wireless router locks up and has to be restarted == * Possible causes: # [[wikipedia:Firmware|Firmware]] bug #* Upgrade firmware to the latest version, downloaded from the manufacturer website. #* In some cases it may be necessary to ask Support for more current "[[wikipedia:Development stage#Beta|beta]]" firmware. #* Upgrade to a better/newer router # [[wikipedia:Address Resolution Protocol|ARP]] cache/table overflow (typically in an older router) #* See ''Firmware bug'' above # Overwhelmed by [[wikipedia:File sharing|peer-to-peer (P2P) filesharing]] application (''e.g., ''[[wikipedia:BitTorrent|BitTorrent]]/[[wikipedia:Azureus|Azureus]], [[wikipedia:eDonkey|eDonkey]]/[[wikipedia:eMule|eMule]]) #* Reduce the ''maximum number of connections'' in the P2P application. Start pretty low and then work up to a maximum safe level. {{Tip|tiptext=Much filesharing is unlawful, and risks serious fines.}} == IPCONFIG fails == If the following error occurs when attempting to run IPCONFIG:<small> Windows IP Configuration An internal error occurred: A device attached to the system is not functioning. Please contact Microsoft Product Support Services for further help. Additional information: Unknown media status code. </small>The likely cause of the problem is a ''wired'' network adapter that isn't connected. IPCONFIG reports an error because of unknown media status from the wired network device driver. This issue is known to affect at least some [[wikipedia:Intel|Intel]] wired network adapters with '''Windows XP''' drivers dated 2006 and later. For example, disconnected Intel PRO/1000 MT Mobile wired network adapter in a [[wikipedia:ThinkPad|ThinkPad]] T41 with driver e1000325.sys: :{| cellpadding=4 cellspacing=0 border=1 style="background:#FFFFEE; font-size:90%; line-height:1.1em;" ! Version !! Date !! Source !! Status || IPCONFIG |- | 6.4.16.36 || 06/13/2003 || Original Windows XP driver || Cable Unplugged || OK |- | 7.2.17.101 || 10/26/2004 || Lenovo Software Installer || Cable Unplugged || OK |- | 8.7.1.0 || 04/27/2006 || Microsoft/Windows Update || Auto Disable || Fails |- | 8.7.9.0 || 10/24/2006 || Lenovo Driver Download || Auto Disable || Fails |- | 8.9.1.0 || 03/25/2007 || Microsoft/Windows Update || Cable Unplugged || Fails |} Apparently this problem was introduced by Intel in Version 8 of its Windows XP drivers, possibly as an [[wikipedia:Unintended consequence | Law of Unintended Consequences]] of power management-related changes. '''Note:''' '''Windows Vista''' does not seem to exhibit this problem with version 8 drivers. ''[Please confirm!]'' '''Fix:''' * Use Windows XP [http://support.microsoft.com/kb/283657 Driver Roll Back] or Uninstall/reboot/reinstall to go back to the original Windows XP driver, or otherwise install an older driver that doesn't exhibit this problem (''e.g.,'' Intel Version 7 rather than Version 8). * Hide any updated driver in Microsoft/Windows Update to prevent unintentionally recreating this problem in the future. Likewise avoid recent driver updates from hardware vendors. '''Workarounds:''' # (Verified) ## Click ''Start'' &rarr; ''Control Panel'' &rarr; ''Network Connections'', and for any ''wired'' network adapters that are ''Disabled'': ## Right-click on ''My Computer'', and click Manage to start ''Device Manager'' ## Disable ''wired'' Network Adapters that are disabled in Network Connections ## Run IPCONFIG as desired ## Re-Enable wired network adapters in ''Device Manager'' # (Verified) ## Click ''Start'' &rarr; ''Control Panel'' &rarr; ''Administrative Tools'' ## Double-click ''Services'' ## Scroll down to ''Routing and Remote Access'' ## If ''Routing and Remote Access'' is ''Disabled'', change it to ''Manual'' ## Start ''Routing and Remote Access'', or Stop and Re-Start it if it's already running # (Not verified, applies to ThinkPads, possibly other computers) ## Uninstall ''Access Connections'', ''Keyboard Customizer'', Wi-Fi drivers, and Ethernet drivers ## Reinstall ''in this order'' Ethernet, Wi-Fi, ''Keyboard Customizer'', ''Access Connections'' '''Notes:''' # Turning off Power Management and/or changing Advanced options doesn't help. # The problem occurs whether or not the Intel PROSet for Windows Device Manager is installed. [[Category:Wi-Fi]]

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