Wi-Fi connection problems

Transcription

1 The possible reasons why a device might not connect to a wireless network on a broadband router include Wi-fi not enabled on router Specific router issues Network name (SSID) & password (often affects Apple devices) Wrong Wireless channel Number of devices allowed to connect simultaneously Incompatible wireless mode Incompatible security mode/encryption MAC address filtering 80211n Bandwidth (Apple devices particlularly) 80211n Guard Interval Huawei HG633 HG635 & other dual band routers Huawei HG633 HG635 SSIDs (network names) not visible Printers & WPS Router firmware recently upgraded Windows XP & WPA2-Personal (AES) encryption Windows Vista Local Only connections No IP Address allocated by DHCP Apple's recommended Wi-Fi settings Page 1 of 32

2 Router Log in To check most of the settings in this document, you will need to log in to your router's web management system To do this open a web browser (eg Internet Explorer, Mozilla Firefox, or Google Chrome) and in the address bar enter this addresshttp// The router will respond with a username/password prompt- enter the detailsusername admin password admin (or your own password if different) Note each Huawei HG633 router has its own unique admin password This can be seen at the top of the label on the rear of the router Once you log in for the first time, you are prompted to change this to a password of your own Location of password- Page 2 of 32

3 Wi-fi not enabled on router Is the Wireless light on the router steady green, if not the wireless may not be enabled On the some routers such as Huawei, this can also be done via the WLAN button on the side of the router To enable the wireless network function, press and hold the WLAN button for over one second, and then release the button To check this via the router's configuration, log into the router ThenHuawei routers & some D-Link DSL-3780s Go into Advanced mode, thenbasic > WLAN Check that "Enable WLAN" is ticked D-Link DSL routers Click the "Advanced" button on the initial summary screens, then click on "Setup" along the top & "Wireless Setup" down the left Next click on the "Manual Wireless Network Setup" button Make sure that the "Enable Wireless" option is ticked- Page 3 of 32

4 Specific router issues D-Link DSL-2780 router - does seem to be a bit hit and miss when it comes to ipads Network Name (SSID) & password Make sure you are connecting to the correct SSID & using the correct password Some devices, particularly Apple ones, do not like any unusual characters in the SSID or password Only use a mixture of upper & lower case letters & numbers Other characters can trigger an AES encryption bug in the device Page 4 of 32

5 Wrong Wireless channel Most routers have their wireless channel set to "Auto", which is OK unless there is interference from other nearby wireless networks etc Setting it to "Auto" is supposed to get the best channel, but it often does not work very well and setting it to a dedicated channel number usually gives better results However, there is a very easy mistake to make here, thinking you can use any of the 11 channels available in the 24GHz band, but in actual fact, you should only use channels 1, 6 or 11 For the reasons behind this seehttp//wwwmetageeknet/support/why-channels-1-6-and-11 To change your channel, logon to your router, go into "Advanced" mode, then it depends on the make/model of router that you have Huawei (not HG635) & some D-Link DSL-3780s Go intobasic WLAN The channel option can be seen below- Page 5 of 32

6 D-Link DSL routers including some DSL-3780s Click on "Setup" across the top tabs and then "Wireless Settings" down the left Then click on the "Manual Wireless Network Setup" button Then in the "Wireless Network Settings" section, the channel number field is hown below- On the 3780 click on Advanced followed by the Advanced Wireless page and look in the WLAN Performance section- Page 6 of 32

7 Huawei HG633/HG635 & other dual band routers Both of these routers are dual band routers, which mean that they have two Wireless Access Points or network names (SSIDs) One operates in the original 24GHz frequemcy band and the other at the newer 5GHz frency band The 24GHz frequency band is not often oversubscribed causing nearby wi-fi networks to interfere with one & other and also it suffers from interference from other devices that operate in this band (wireless door bells, DECT cordless phones, video senders & microwave ovens etc) The 5GHz band does not suffer from this & gives a better range A lot of other routers non TalkTalk routers are available as dual band routers One of the first problems though with these two router models, is by default it is difficult to know which frequency band you have connected to, because they use the same network name (SSID) for both bands So it is best to log into the router and give them different names Then click on the "Home Network" tab followed by "Wireless Settings" on the left & expand the "Encryption" section in the main pane Set each network name (SSID) to a different name & make sure both are enabled- To get any device to connect to the 5GHz band, it must also have a dual band network card in it A lot of devices on sale currently are still only single band devices & if only the 5GHz band is enabled, then they will not be able to connect to the router Page 7 of 32

8 Huawei HG635 Super Router This router is different to most others in the TalkTalk range, once logged on, click on the "Home Network" tab at the top Click on "Wireless Settings" down the left Scroll down the page to "Advanced Settings" & expand that if minimised There you will find the channel setting, one for the 24GHz band and another further down for the 5GHz band This is the one for the 24Ghz band- Note in some rare cases, after setting the 24GHz channel to a dedicated number, some devices can no longer detect the network name (SSID) If this is the case, also in the "Advanced Settings" section, set the 80211n bandwidth to 20MHz and the 80211n guard interval to Short in the 24GHz band You may also need to set the 80211n/ac guard interval to Short in the 5GHz band as well Page 8 of 32

9 SSID (network name) & Wireless Password Try renaming your SSID (network name) to remove the hyphen (-) used in the default "TALKTALK-xxxxxx" SSID If using your original wireless password, also remove any hyphen characters from it Alternatively use your own password, but do not use any "odd" characters in the password, with some MAC OSX versions, this triggers an AES encryption bug and causes connection problems The wireless password can be changed by logging into the router, click on "Advanced" Huawei & some DSL-3780 routersgo tobasic > WLAN Then enter the new SSID in the SSID field & the password in the "WPA pre-shared key" field- Page 9 of 32

10 On D-Link DSL routers(inc some DSL-3780s) Go to the "Setup" tab at the top, then "Wireless Settings" on the left Then click on the "Manual Wireless Network Setup" button, go to the "Wireless Network Settings" section Enter the new SSID in the "Wireless Network Name (SSID)" field- For the password, go down to the "Pre-shared key section Enter the new password there Page 10 of 32

11 Number of devices allowed to connect simultaneously This can be caused by the DHCP server in the router having a too small start & finish IP address range Some routers also restrict the number of simultaneous devices allowed to connect to the router's wireless network With a standard TalkTalk configuration, this can be increased up to a maximum of 253 If you log on to the router & go into advanced mode, then depending on the router you have check these two settings Huawei (not HG635) DHCP server Basic > LAN > DHCP This should be set as follows- Max Number of devices Basic > WLAN Page 11 of 32

12 D-Link routers DHCP Click the "Setup" tab along the top & "LAN Setup" down the left In the DHCP section, set them as follows- There does not seem to be any option to limit the number of simultaneous connections Huawei HG635 Super Router DHCP Click on the "Home Network" tab across the top and then "LAN Interface" down the left In the DHCP Server section, set the address range as follows- There does not seem to be any option to limit the number of simultaneous connections Page 12 of 32

13 Incompatible Wireless Mode When a device tries to connect to a router, there is a negotiation that takes place to find a common wireless mode This negotiation is between the device's network card and the router, it has no direct relationsionship between the network card & the device's operating system The check for a compatible security mode/encryption is only done after a succesful negotiation of the wireless mode & has no direct relationship to it If this negotiation fails to find a common mode, then the device will not be able to connect to the router If a router is set to 80211n only and some devices can only work up to 80211g, they will not be able to connect Log into the router & then follow the guidance based on the router concerned Huawei router & some DSL-3780s Go into Advanced mode, thenbasic > WLAN Page 13 of 32

14 D-Link DSL routers (including only some DSL-3780s) Click on the "Advanced" button in the initial summary screens Then go to the "Setup" tab at the top, then "Wireless Settings" on the left Then click on the "Manual Wireless Network Setup" button- The Wireless Mode setting is shown below- Page 14 of 32

15 Incompatible security mode/encryption wrong When a device tries to connect to a router, if they have succesfully found a compatibe wireless mode between the device's network card & the router, then the security mode/encryption is checked This time the negotiation concerns the router & the device's operating system (eg Windows), not its network card They are checking for a common standard this time consisting of a combination of the security mode, as well as the encryption used If the router forces a paricular security mode/encryption setting that a device's operating system does not support, then that device will be unable to connect to the router If the router is configured to only use the WPA2-Personal security mode with AES encrption (the current recommended security settings) and device does not support this, it will not connect This can be a particular problem with Windows XP not even running service pack 2 How to identify security settings in use- The security type is WPA2-PSK in the example above, the PSK standing for Pre-Shared Key This Pre-Shared Key is your wireless password, or more correctly called passphrase However, this does not specify the encryption in use, but it has to be one of two1 TKIP (Temporal Key Integrity Protocol) This was a stopgap encryption protocol introduced with WPA to replace the very-insecure WEP encryption at the time TKIP is actually quite similar to WEP encryption TKIP is no longer considered secure, so should not be used 2 AES (Advanced Encryption Standard) It is also known as "Counter mode Cipher block chaining Message authentication code Protocol" (CCMP) This protocol used by WPA2, is based on the Advanced Encryption Standard (AES) cipher along with strong message authenticity and integrity checking that is significantly stronger in protection for both privacy and integrity than the RC4-based TKIP used by WPA and the original implementation WPA2 Among informal names are "AES" and "AES-CCMP" The 80211n specification states that this encryption protocol must be used to achieve the fast 80211n high bitrate schemes, though not all implementations enforce this Otherwise, the data rate will not exceed 54 MBit/s Page 15 of 32

16 Right click the connection & choose properties, both the security mode & the encryption type can be seen here- Check router configuration This router os configured to only use the WPA2 Personal security mode with AES encryption- In more detail- Page 16 of 32

17 MAC (Media Access Control) Address Filtering If any MAC address filtering has been setup to only allow certain devices MAC addresses to connect to a Wi-Fi network, any new devices must be allowed via the router's configuration, before they will be able to connect to the router Most routers support a whitelist (only these devices can connect) & a blacklist (any device can connect except these specific devices) The Whitelist is the one that should be used, as it is more secure than the blacklist Huawei routers & some D-Link DSL-3780s D-Link DSL & some DSL-3780 routers Huawei routers & some D-Link DSL-3780s Login to the router and click the Advanced tab on the left, then go tobasic > WLAN Click on the "WLAN Filtering" tab along the top If the "Enable" option is ticked, then filtering is active Select the "Whitelist" and a list of all of the MAC addresses of the devices that are currently allowed, will be seen Check if the device in question has it's MAC address allowed- Page 17 of 32

18 D-Link DSL routers(icluding some DSL-3780s) To display the "Whitelist" for a D-Link, log into the router & click on the "Advanced" button in the initial summary screens Then click on the "Advanced" tab along the top, followed by "Wireless MAC Filter" If any MAC address filter currently exists the "Status" will be "Activated" and the "Action" set to "Allow Association" The list of allowed MAC addresses will be dispalyed in the list below Check if the device in question has it's MAC address in this list- Page 18 of 32

19 80211n Bandwidth or channel bonding (Apple devices particularly) First what this parameter is for & then why some Apple devices do not like it Traditional channels are 20 MHz wide, The ability to add a second channel was introduced with 80211n, older standards 80211b or g do not support this It is supported in both the 24 & 5GHz frequency bands, but it works best in the 5GHz band This is because there is only space for three traditional, non-overlapping channels in the 24GHz frequency band (channels 1, 6 & 11) Therefore, there is only enough space for one bonded channel in that portion of the RF spectrum With 5GHz, there are over 20 non-overlapping channels, so you can have several bonded channels operating within close proximity to each other without co-channel interference There can be problems using a 40MHz channel bandwidth setting in the 24GHz band, particularly if you use a lot of bluetooth devices, as the two can clash In the 5GHz band it is really a no brainer (unless Apple), always use it Depending on the make/model of router this can be called n bandwidth Channel width Bandwidth Channel bonding You may see your network card reporting a speed or bandwidth of 150 or 300Mbps in the connection status (see this example from Windows 7)- The settings for this (depending on make/model of router) is 20/40MHz or some combination of the two on Huawei routers Some routers now even off 60Mhz as an option (3 channels) Page 19 of 32

20 On some D-Link routers the options for this setting are confusingly labelledsetting No of channels used Frequency width Up to 270Mbps 1 20MHz Forces to 300Mbps 2 40MHz Taking the Huawei as an example, if using the option "20/40MHz" the router will negotiate with the network card when a wireless connection between the two is established Both devices will use the highest supported common setting So if the network card only supports a bandwidth of 150Mbs, the they will both only work at 150Mbps, even though the router can run at a higher bandwidth If the network card supports 150, 300 and greater bandwidth settings, the highest common one is 300Mbps Assuming the router is setup to use wireless channel 6, and the router & network card have negotiated to use 40MHz This means that channel 6 can handle a bandwidth of 150Mbps, but that it requires an extra channel to use, if the amount of data flowing across your network card exceeds 150Mbps That extra channel it can then use is channel 10 This allows up to a total of 300Mbps when using both channels Depending how technical you are, why am I one moment talking Mbps and then in frequencies MHz? Each channel on an 80211n uses a 20MHz frequency band Some D-Link routers show the setting as "Channel Width" and give it in Mbps Apple This all sounds great, unless you use any Apple devices, as they don't particularly like the 20MHz/40MHz 80211n bandwidth This can cause these devices not to be able to find the wi-fi network in question To check this log into the router & follow as per the particular router Note if you want to use the increased bandwidth this option offers, then if at all possible lock the router down to 80211n mode only If set to allow connections on "b, g or n" and a device running 80211g connects to the router for eaxample, all devices then have to run at 80211g and this facility is no longer available Page 20 of 32

21 Huawei & some DSL-3780 routers Go into Advanced mode, then go to Basic > WLAN In there change the "11N band width" option from 20/40Mhz to just 20MHz & see how that goes Page 21 of 32

22 D-Link DSL routers & DSL-3780s Click the "Advanced" button from the initial summary screens & click on "Advanced" tab along the top, followed by "Advanced Wireless" on the left Set the banwidth based on what is required, if it uses one channel this is the equivalent of 20MHz & two channels uses 40MHz Some D-Link routers do not have the "Up to 270MHz" option and so the best that can be acheived here is "Up to 135MBps", which is 1 channel with a frequency width of 20MHz anyway On the 3780 the bandwith option is in the "WLAN Performance" section, which is off "Advanced Wireless" down the left hand side- Please see next page Page 22 of 32

23 Here the bandwidth option is called "Channel Width", this is it set to use two channels (40MHz) Forces to 300Mbps - Here is it set to use one channel (the equivalent of 20MHz) up to 270Mps - More details on this settinghttp//wwwpcmagcom/article2/0,2817, ,00asp Page 23 of 32

24 Guard Interval The guard interval is the space between symbols (characters) being transmitted This is often confused with the space between packets, which is the inter-frame space (IFS) The guard interval is there to eliminate inter-symbol interference, which is referred to as ISI ISI happens when echos (reflections) from one symbol interfere with another Adding time between symbol transmissions allows these echos to settle out before the next symbol is transmitted In normal operation, the guard interval is 800 ns With 80211n, shorter guard intervals are possible The short guard interval time is 400ns, or half of what it used to be Shorter wait time (guard interval) between symbols increases throughput However, if it's too short, the amount of ISI will increase, and throughput will decrease On the other hand, if the guard interval is too long, there is increased overhead due to the additional idle time Using Short Guard Interval increases the data rate by roughly 10-11% On Huawei routers, look in Basic > WLAN, however, unless firmware updates have made it configurable, it is not an available option in the D-Link routers This parameter is included in this document, because some devices may not like a short guard interval & therefore may not be able to connect to this network Page 24 of 32

25 HG635 SSIDs not visible There can be a problem under certain configurations, where a dedicated channel number on the 24GHz band and Auto on the 5GHZ, causes the 24GHz to SSID to disappear (particularly with Apple devices & Nexus phones, but it can even happen on a PC) If this is the case, go tohome Network > Wireless Settings In the "Advanced Settings" section, set the 80211n bandwidth to 20MHz and the 80211n guard interval to Short in the 24GHz band You may also need to set the 80211n/ac guard interval to Short in the 5GHz band as well Page 25 of 32

26 Printers & WPS WPS (Wireless Protected Setup) only works on wireless networks that have WPA Personal or WPA2 Personal security mode in use Some printers do not like a Network Name (SSID) of longer than 8 characters when trying to establish a WPS connection If you are having issues consider reducing the length of the SSID to no more than 8 characters in length & try not use an special characters such as hyphens (-) or other symbols It is best to stick to alphanumeric characters or either case If you have a dual band router, try to use a different SSID for the 24GHz and 5GHz bands, otherwise it can be difficult to know which band a device is connected to Once the connection has been established via WPS OK, it is always worth disabling the WPS facaility within the router, as it can be regarded as a security risk associated with the WPS PIN number For details please seehttps//enwikipediaorg/wiki/wi-fi_protected_setup#vulnerabilities Despite being disabled, all connections previously connected via WPS will remain connected Router firmware recently upgraded If your router has recently had it's firmware upgraded to a different version, it can behave unexpectedly like this, until a factory reset has been performed on the router Waning this will cause all configuration data that you have put into the router yourself, to be lost I have produced a guide on how to perform a factory default on the TalkTalk routers & get back on line Please let me know if you want a copy & I'll attach it to your thread Page 26 of 32

27 Windows XP & WPA2 Personal encryption With 80211n all consumer routers should be running the security mode "WPA2 Personel" with AES encryption Windows XP, even after updating drivers, will often be trying to use WPA TKIP by default Before changing the encryption to AES type, the XP machine MUST be running SP2 at least, so if it hasn't been updated with all service packs, you will need to do this, as well as updating adapter drivers, update it to SP3 for best results! Once your machine has new drivers and all Service Packs installed, XP needs to be set to AES and not TKIP type encryption1) Go to Start and click on Control Panel 2) Control Panel window will appear Double click on Network Connections 3) Network Connections window will appear Right click correct Wireless Network Connection 4) Wireless Network Connection Properties will appear Click Wireless Networks tab 5) Tick Use Windows to configure my wireless network settings Click Add to create preferred wireless network, or view wireless networks to change properties of the existing connection 6) Wireless Network Properties window will appear Here is the place you key in your wireless network information, it must match with the settings you set on wireless router If not, you will fail to join the network Key in SSID of your wireless network Set "Network Authentication" to "WPA2-PSK" & "Data encryption" to "AES" Page 27 of 32

28 Windows Vista & Local Only connections This tends to be caused by Windows Vista not liking the network adapter being configured for IP V6 See this search through YouTube where these videos show how to resolve the issue No IP Address allocated by DHCP Once connected to a wireless network, your device needs an IP address, before it can communicate with the router or internet In fact it actually needs four things, all of which are normally allocated by the DHCP server in the router The required information below gives some example addresses etc & may vary on your network IP address Subnet mask Default gateway DNS server(s) (eg ) (eg ) (eg the same IP address as the router) (eg the same IP address as the router) So if connected, but can't access the router or internet, were you allocated these correctly? This can normally be checked quite easily, but varies with the type of device you are trying to connect with Some of the possible devices are shown in this document Windows PC or Laptop Windows Phone Apple MacBook, iphone or ipad Android phones Page 28 of 32

29 Windows PC & Laptop Go tostart > All Programs > Accesories > Command Prompt issue the commandipconfig /all In this example the PC is connected by wireless and the ethernet cable is diconnected If you are trying to connect via an ethernet cable, you will see what IP address etc you have been allocated, only if the "Media State" shows as "Connected" The addresses & subnet mask required are highlighted in yellow belowwindows IP Configuration Host Name Primary Dns Suffix Node Type IP Routing Enabled WINS Proxy Enabled My-PC Hybrid No No Wireless LAN adapter Wireless Network Connection Connection-specific DNS Suffix Description Physical Address DHCP Enabled Autoconfiguration Enabled Link-local IPv6 Address IPv4 Address Subnet Mask Lease Obtained Lease Expires Default Gateway DHCP Server DHCPv6 IAID DHCPv6 Client DUID <--Wireless settings section TP-LINK Wireless N Adapter B2-56-D1 Yes Yes fe80982baaf47d397402%11(preferred) Friday 31 October Saturday 01 November CC E8 DNS Servers NetBIOS over Tcpip Enabled Ethernet adapter Local Area Connection Media State Connection-specific Description Physical Address DHCP Enabled DNS Suffix <--Ethernet cable (wired) settings section Media disconnected <--If cable used & shows home disconnected check connection Realtek PCIe GBE Family Controller B7-55-B8 Yes IP address starts with 169xxx Windows uses this address whenever the DHCP IP address allocation procedure fails If this is the address allocated to your Windows PC/Laptop, go back to the Command Prompt & enter this command In most cases this will get you a valid IP addressipconfig /renew Page 29 of 32

30 Windows Phone To find the IP address information allocated on a Windows 81 phone, touch "Settings" then "Wi-Fi" Find your network you are connected to from the list & touch it The DHCP allocated information will be seen further down the resulting page iphone, ipad & MacBook On the ipad etc, tap on the Settings icon- Then tap on General and Wi-Fi and look for the network name you are connected to Next tap the blue arrow next to it This will display the wireless TCP/IP configuration settings Click on the DHCP tab below- To renew the IP address, click the "Renew Lease" button above Page 30 of 32

31 Android Phones Note with all vesrions of android, they will only show the phone's IP address, not the subnet mask, default gateway, or DNS servers To display everything you would need an Android app such as"ipconfig -Get MAC IP ADDRESS" This app was just selected from Play Store but was not tested Android 2x Open Settings Touch Wireless & Networks Then press the Menu key & choose Advanced Look at the IP Settings section Android 3x Open Settings Touch Wireless & networks on the left Touch Wi-Fi settings Then press the Menu key & choose Advanced Look at the IP Settings section Android 40 Open Settings Under the Wireless & networks heading on the left, Touch Wi-Fi Then press the Menu key & choose Advanced Look at the IP Settings section Android 41 & later Tap Settings > Wi-Fi Then press the Menu key & choose Advanced Look at the IP Settings section Page 31 of 32

32 Apple's recommended Wi-Fi settings Seehttps//supportapplecom/en-is/HT Page 32 of 32