Sunday, 27 July 2014

WIRELESS NETWORK-CONNECTION,MAINTENANCE AND SECURITY



            Most WiFi wireless access points / routers claim to support up to 255 connected devices. Access points and routers support a small number (usually either 1 or 4) of wired Ethernet and the rest via wireless connections.
Connecting 255 computers to a single WiFi access point, while theoretically possible, is not recommended. Performance of such a network will be very poor. Install multiple access points instead to distribute the network load. By adding more access points to the network, effectively any number of computers can be supported (though the network becomes progressively more difficult to manage).
On a home network, while dozens of computers and other devices may connect to the router, the performance of a shared Internet connection will quickly degrade as more computers access the Web simultaneously.
Wireless network connection
Key Considerations -
All devices connecting to a wireless router must possess a working network adapter. As illustrated in the diagram, connecting to the router a broadband modem (that has one or more built-in adapters) enables sharing of a high-speed Internet connection.
Wireless routers technically allow dozens of computers to connect over WiFi links. Nearly any residential wireless router will have no trouble supporting the number of wireless devices found in typical homes. However, if all WiFi computers attempt to use the network at the same time, slowdowns in performance should be expected.
Many (but not all) wireless network routers also allow up to four wired devices to be connected via Ethernet cable. When first installing this kind of home network, one computer should be cabled to the wireless router temporarily to allow initial configuration of the wireless features. Employing Ethernet connections after that is optional. Using permanent Ethernet connections make sense when the computer, printer or other device lacks WiFi capability or cannot receive an adequate wireless radio signal from the router.
Optional Components - Networking the router for Internet access, printers, game consoles and other entertainment devices is not required for the rest of the home network to function. Simply omit any of these components shown that do not exist in your layout.
Limitations - The WiFi portion of the network will function only to the limit of the wireless router's range. The range of WiFi equipment varies depending on many factors including layout of the home and any radio interference that may be present.
If the wireless router does not support enough Ethernet connections for you needs, add a secondary device like a network switch to expand the wired portion of the layout.




Steps to connect to a wi-fi modem

1. Plug Broadband Modems into the Correct Port on Wireless Routers

Several network cables often are required even on so-called wireless networks. The one connecting the broadband modem to the broadband router is especially critical as Internet service can’t be distributed through the home without it. A modem cable can physically join to several different places on a router, but be sure to connect it to the router’s uplink port and not some other port: Broadband Internet will not work through a router unless its uplink port is used. (Residential gateway devices that combine both a router and modem into a single unit do not require this cabling, of course).

2. Use an Ethernet Cable for Initial Setup of Wireless Routers

Configuring the Wi-Fi settings on a wireless router requires connecting to the unit from a separate computer. When performing initial router setup, make an Ethernet cable connection to the computer. Vendors supply free cables with most new routers for this purpose. Those who try to use their wireless link during setup often encounter technical difficulty as the router’s Wi-Fi may not work properly until fully configured.

3. Install Broadband Routers in Good Locations

The wireless transmitters of home broadband routers normally can cover all the rooms in a residence plus outdoor patios and garages. However, routers located in corner rooms of larger homes may not reach the desired distances, particularly in buildings with brick or plaster walls. Install routers in more central locations where possible. Add a second router (orwireless access point) to a home if necessary. 

4. Reboot and/or Reset Routers and Other Equipment

Technical glitches can cause wireless routers to freeze or otherwise start malfunctioning during setup. Rebooting a router allows the device to flush its non-essential temporary data, which can resolve some of these issues. A router reset differs from a router reboot. In addition to flushing non-essential data, router resets also erase any customized settings entered during setup and restore the unit to its original default settings as configured by the manufacturer. Router resets afford administrators a simple way to start over from botched attempts at setup. Just as wireless routers can benefit from a reboot, some other devices on a wireless network may also require rebooting during the setup process. A reboot is an easy and relatively quick way to ensure unrelated glitches on the device are not interfering with network operation and that any settings changes have taken permanent effect. 

5. Enable WPA2 Security on Wi-Fi Devices (if possible)

An essential security feature for Wi-Fi networks, WPA2 encryption keeps data mathematically scrambled while it travels over the air between devices. Other forms of Wi-Fi encryption exist, but WPA2 is the most widely supported option that offers a reasonable protection level. Manufacturers ship their routers with encryption options disabled, so enabling WPA2 on a router typically requires logging into the administrator console and changing the default security settings. 

6. Match Wi-Fi Security Keys or Passphrases Exactly

Enabling WPA2 (or similar Wi-Fi security options) requires choosing a key value or passphrase. These keys and passphrases are strings - sequences of letters and/or digits - of varying length. Every device must be programmed with a matching string to be able to communicate with each other over Wi-Fi with security enabled. When setting up Wi-Fi devices, take special care to enter security strings that match exactly, avoiding transposed digits or letters in upper instead of lower case (and vice versa).






Ad hoc network


Key Considerations - Using ad hoc wi-fi mode eliminates the need for a network router oraccess point in a wireless home network. With ad hoc wireless, you can network computers together as needed without needing to be in reach of one central location. Most people use ad hoc Wi-Fi only in temporary situations to avoid potential security issues.
Optional Components - Networking an ad hoc layout for Internet access, printers, or game consoles and other entertainment devices is not required for the rest of the home network to function. Simply omit any of these components shown that do not exist in your layout.
Limitations - All devices connecting via ad hoc wireless must possess a working Wi-Fi network adapter. These adapters must be configured for "ad hoc" mode instead of the more typical "infrastructure" mode.
Because of their more flexible design, ad hoc Wi-Fi networks are also more difficult to keep secure than those using central wireless routers / access points.
Ad hoc Wi-Fi networks support a maximum of 11 Mbps bandwidth, while other Wi-Fi networks may support 54 Mbps or higher.


Steps to connect a Ad hoc network
1.      For each of the computers (devices) to be connected via ad hoc networking, determine whether they have Wi-Fi capability. Purchase and install Wi-Fi network adapter hardware if needed.
2.      Decide on a name and a Wi-Fi security password for the ad hoc network to be created.
3.      To set up an ad hoc Wi-Fi connection in Microsoft Windows, first choose the "Set up a new connection or network" option in Network and Sharing Center, then choose the "Set up a wireless ad hoc (computer-to-computer) network" option and click Next to start the process. Follow the instructions provided with each step.
4.      To set up ad hoc Wi-Fi from Mac OS X, choose the "Create Network..." menu option from AirPort (usually accessible from the main menu bar), then choose the "Create a Computer-to-Computer Network" option and follow the instructions provided.
5.      Test the ad hoc network connection after linking the first two devices together.
6.      To join additional devices to an established ad hoc network, browse the list of Wi-Fi networks it has discovered and connect to the one with the correct name.

Tips:

1.      When using ad hoc mode, be aware of several security issues and performance limitations of ad hoc Wi-Fi networks.
2.      The most common sources of trouble in ad hoc mode networking are incorrect configuration and insufficient signal strength. Ensure your devices are located close enough to each other, and ensure configuration settings are made identically on each device.


Wifi trouble shooting

1. Wi-Fi Radio Interference

Radio signals from various consumer electronic products can interfere with Wi-Fi wireless network signals. For example, cordless phones, Bluetooth devices, garage door openers and microwave ovens can each take down a Wi-Fi network connection when powered on. You can move your network equipment or (on home networks) change some Wi-Fi radio settings to avoid this problem.

2. Insufficient Wi-Fi Network Range and Power

Even without interference from other equipment, Wi-Fi connections can drop occasionally on devices located near the edge of the network's wireless signal range. Wi-Fi links generally become more unstable with distance. Relocating your computer or other gear is a simple but not always practical solution. Otherwise, consider antenna upgrades and other techniques to improve wireless signal transmission and reception.

3. Unknowingly Connecting to the Wrong Wi-Fi Network

If two neighboring locations run unsecured Wi-Fi networks with the same name (SSID), your devices may connect to the wrong network without your knowledge. This can cause the interference and range problems described above. Additionally, in this scenario your computers will lose connection whenever the neighbor network is turned off, even if your preferred one remains functional. Take proper security measures to ensure your computers connect to the right network.

4. Network Driver or Firmware Upgrade Required

Each computer connected to a Wi-Fi network utilizes a small piece of software called the device driver. The Wi-Fi network device driver controls various functions of the Wi-Fi hardware.Network routers contain related technology called firmware. Network drivers and firmware can both become obsolete over time. Upgrading (overinstalling) newer versions of these things can sometimes fix network connection problems. Get free upgrades from the manufacturer's Web sites.

5. Incompatible Software Packages Installed

Wi-Fi network connections may start failing on a computer due to incompatible software installed and running there. This includes operating system patches, operating system services, and other software that modifies the networking capabilities of the operating system. Keep records of each time you install or upgrade software on your computers, and be prepared to uninstall any incompatible software you've added recently.

6. Overloading / Overheating the Wireless Access Point

Owners of some wireless routers  have reported dropped connections during times of heavy network utilization. This can occur during, for example, online gaming or while copying large files. Routers can in theory become overloaded with too much data and fail temporarily. If a router's temperature increases too much, it may also fail until cooled. Install routers (access points) in places with good airflow. Exchange the router for a different unit if the current one doesn't support your usage patterns.






Wireless security

1. Change Default Administrator Passwords (and Usernames)

At the core of most Wi-Fi home networks is an access point or router. To set up these pieces of equipment, manufacturers provide Web pages that allow owners to enter their network address and account information. These Web tools are protected with a login screen (username and password) so that only the rightful owner can do this. However, for any given piece of equipment, the logins provided are simple and very well-known to hackers on the Internet. Change these settings immediately.

2. Turn on (Compatible) WPA / WEP Encryption

All Wi-Fi equipment supports some form of encryption. Encryption technology scrambles messages sent over wireless networks so that they cannot be easily read by humans. Several encryption technologies exist for Wi-Fi today. Naturally you will want to pick the strongest form of encryption that works with your wireless network. However, the way these technologies work, all Wi-Fi devices on your network must share the identical encryption settings. Therefore you may need to find a "lowest common demoninator" setting.

3. Change the Default SSID

Access points and routers all use a network name called the SSID. Manufacturers normally ship their products with the same SSID set. For example, the SSID for Linksys devices is normally "linksys." True, knowing the SSID does not by itself allow your neighbors to break into your network, but it is a start. More importantly, when someone finds a default SSID, they see it is a poorly configured network and are much more likely to attack it. Change the default SSID immediately when configuring wireless security on your network.

4. Enable MAC Address Filtering

Each piece of Wi-Fi gear possesses a unique identifier called the physical address or MAC address. Access points and routers keep track of the MAC addresses of all devices that connect to them. Many such products offer the owner an option to key in the MAC addresses of their home equipment, that restricts the network to only allow connections from those devices. Do this, but also know that the feature is not so powerful as it may seem. Hackers and their software programs can fake MAC addresses easily.

5. Disable SSID Broadcast

In Wi-Fi networking, the wireless access point or router typically broadcasts the network name (SSID) over the air at regular intervals. This feature was designed for businesses and mobile hotspots where Wi-Fi clients may roam in and out of range. In the home, this roaming feature is unnecessary, and it increases the likelihood someone will try to log in to your home network. Fortunately, most Wi-Fi access points allow the SSID broadcast feature to be disabled by the network administrator.

6. Do Not Auto-Connect to Open Wi-Fi Networks

Connecting to an open Wi-Fi network such as a free wireless hotspot or your neighbor's router exposes your computer to security risks. Although not normally enabled, most computers have a setting available allowing these connections to happen automatically without notifying you (the user). This setting should not be enabled except in temporary situations.

7. Assign Static IP Addresses to Devices

Most home networkers gravitate toward using dynamic IP addresses. DHCP technology is indeed easy to set up. Unfortunately, this convenience also works to the advantage of network attackers, who can easily obtain valid IP addresses from your network's DHCP pool. Turn off DHCP on the router or access point, set a fixed IP address range instead, then configure each connected device to match. Use a private IP address range (like 10.0.0.x) to prevent computers from being directly reached from the Internet.

8. Enable Firewalls On Each Computer and the Router

Modern network routers contain built-in firewall capability, but the option also exists to disable them. Ensure that your router's firewall is turned on. For extra protection, consider installing and running personal firewall software on each computer connected to the router.

9. Position the Router or Access Point Safely

Wi-Fi signals normally reach to the exterior of a home. A small amount of signal leakage outdoors is not a problem, but the further this signal reaches, the easier it is for others to detect and exploit. Wi-Fi signals often reach through neighboring homes and into streets, for example. When installing a wireless home network, the position of the access point or router determines its reach. Try to position these devices near the center of the home rather than near windows to minimize leakage.

10. Turn Off the Network During Extended Periods of Non-Use

The ultimate in wireless security measures, shutting down your network will most certainly prevent outside hackers from breaking in! While impractical to turn off and on the devices frequently, at least consider doing so during travel or extended periods offline. Computer disk drives have been known to suffer from power cycle wear-and-tear, but this is a secondary concern for broadband modems and routers. 

If you own a wireless router but are only using it wired (Ethernet) connections, you can also sometimes turn off Wi-Fi on a broadband router without powering down the entire network.






No comments: