Server and intenet connectivity issues.

Server Connectivity Issues:

DNS: The DNS translates Internet domain and host names to IP addresses. DNS automatically converts the names we type in our Web browser address bar to the IP addresses of Web servers hosting those sites.

DNS Issues:

•When something is wrong with the DNS configuration on a computer or the DNS server on a network, client computers cannot resolve computer names or FQDNs to their IP addresses, and connectivity to resources fail .

• Then user should check the DNS settings on the local computer if:

–After analyzing the results of Ping, Ipconfig /all, Tracert, or other command-line tests, the user feels that an incorrect DNS configuration is preventing from resolving names to IP addresses.

–The user have verified the IP address of the DNS server.

–The user have checked that the server is online.

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WINs : Designed specifically to support NetBIOS over TCP/IP (NetBT). WINS is required for any environment in which users access resources that have NetBIOS names. If you do not use WINS in such a network, you cannot connect to a remote network resource by using its NetBIOS name unless you use Lmhosts files, and you might be unable to establish file and print sharing connections.

It is just a database file which contains all computer names present within a network and their Ip addresses.

WINS Issues :

–WINS integration is necessary only if the network includes computers running previous versions of Windows.

•The user should check the WINS settings on the local computer if:

–The user believes that an incorrect WINS configuration is preventing a computer from resolving NetBIOS names to IP addresses.

–The user have verified the IP address of the WINS server.

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How to confifure Tcp/ip

Steps:

Control Panel >Double-click the Network and Sharing Center icon .

In Network and Sharing Center, Click on Change adapter settings to look at various connections available.

–Right-click the Local Area Connection icon.

–Select Properties >

To install (re-install) TCP/IP and  in Windows 7.

•To install TCP/IP:

–In the Local Area Connection Properties dialog box, highlight Internet Protocol (TCP/IPv4)

*Click the Install button

*A new dialog box will display asking for the Network Component Type to install

*Highlight Protocol

*Click Add button

*The list of network protocols will be displayed.

*Since Internet Protocol (TCP/IP) is not displayed, it will be necessary to locate it.

*Click the Have Disk button

* In the Install From Disk dialog box, it will be necessary to either type the path, or browse to the location on the machine.

*Type the following in the drop-down text box: C:\WINDOWS\INF

*Click the Browse button

*Once the Locate File window appears, locate the following file: nettcpip.inf

*Once it is located, highlight the file and click the Open button

*A new Select Network Protocol dialog box will appear.

*Highlight Internet Protocol (TCP/IP)

*Click OK

*The system will pause for a moment, but nothing else will happen

*TCP/IP will be installed (re-installed)

How to configure DHCP TCP/IP and in Windows 7

*In the Local Area Connection Properties dialog box, highlight Internet Protocol (TCP/IPv4)

*Click the Properties button

*Choose the Obtain an IP address automatically radio button.

*This will cause the computer to request an IP address from the DHCP server when it boots.

How to configure Static TCP/IP and in Windows 7

To set a static IP address, click the Use the following IP address radio button

–The IP address, subnet mask, and default gateway addresses are required to be filled in if this button is selected.

Additional settings may include the addresses for the DNS servers (which resolves FQDN to IP) and the WINS servers (which resolves NetBios names to IP)

–To set these addresses click Advanced

In Advanced TCP/IP Settings window, the IP Settings tab identifies if DHCP is enabled for the computer

*A static IP address or Default Gateway (if required) can be added here.

*The DNS tab allows additional DNS server addresses to be added.

*DNS is responsible for resolving Fully Qualified Domain Names to IP addresses

*DNS Suffixes are domain names for resources residing on a specific domain in a network.

*The WINS tab allows additional WINS servers to be added

*The LMHOSTS is a file on the local machine that retains a list of NetBIOS names of resources on a network with their IP addresses.

Troubleshooting:

IPCONFIG /all : Is used to check ip address of computer and MAC address of NIC.

When you use this command and if you get all Zeros for physical address, then NIC is not working.

Ping loopback (127.0.0.1) : This address is reserved by IANA to test the TCP/IP stack

This is the loopback address used to test for TCP/IP components and the computer’s ability to communicate.

If you get request time out error.

Then make sure to Check TCP/IP settings to confirm if the communications protocol is installed.

If it is installed, re-install TCP/IP with directions provided earlier in the module.

Ping default gateway (router port address) : This address can be found using IPCONFIG and this checks the connection out of the subnet.

If you see any failure message,

*Then check cables and connections between the switch or hub, and the default gateway.

*Check the IP address and subnet mask of the default gateway

*Check the default gateway data-link protocol equipment and the local computer data-link protocol equipment

Ping a Fully Qualified Domain Name:

This address is a Fully Qualified Domain Name on the Internet (e.g., www.google.com) Ex :  ping www.google.com in command prompt.

If you get positives results, then its working fine.

But if you get request time out error, then follow the steps given below:

*Check cables and connections between the switch or hub, and the default gateway

*Check the IP address and subnet mask of the default gateway

*Check the default gateway data-link protocol equipment and the local computer data-link protocol equipment.

If you are in Office network connected to a Domain, then  Ping domain server name (optional depending on issues) :

This address can be found at the logon screen

This checks that connectivity exists between the domain server and the local computer

The domain server provides authenticated access to the domain.

If you face any login issue:

* Check cables and connections between the switch or hub, and the default gateway

* Check the IP address and subnet mask of the default gateway

* Check the default gateway data-link protocol equipment and the local computer data-link protocol equipment.

Ping DNS server (optional depending on issues) : This address can be found using IPCONFIG /all. This checks connectivity with the server that resolves FQDNs to IP addresses

If DNS not working, then Ping to check that the DNS server is not down

*If the DNS server is down and another DNS server exists, modify TCP/IP Properties to replace the DNS server.

Ping WINS server (optional depending on issues) :This address can be found using IPCONFIG /all. This checks connectivity with the server that resolves NetBIOS names to IP addresses.

The WINS server will resolve NetBios names to IP addresses.

For any issues

*Check that the WINS server is not down

*If the WINS server is down and another WINS server exists, modify TCP/IP Properties to replace the WINS server

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How to find the MAC address of the computer:

A MAC (Media Access Control) address is a number that identifies the network adapter(s) installed on your computer. The address is composed of up to 6 pairs of characters, separated by colons. You may need to provide your MAC address to a router in order to successfully connect to a network. To find your MAC address on any system with a network connection, use one of the following methods.

Method 1: Using Windows Vista, 7, or 8

Connect to a network. This method is only applicable if you are currently connected. Make sure to connect with the interface that you need the MAC address for (Wi-Fi if you need your wireless card’s MAC address, Ethernet if you need your wired card’s MAC address).

Click on the connection icon in the system tray. It may look like a small graphic (see above image), or like a tiny computer monitor. After clicking on it, select "Open Network and Sharing Center".

• In Windows 8, run the Desktop application in your Start screen. Once you’re in Desktop Mode, right-click on the connection icon in the system tray. Select “Network and Sharing Center”.

Find the name of your network connection and click on it. It will be located right after the word Connections. This will open a small window.

Click Details. This will open a list of configuration information about the connection, similar to what appears when you use the IPConfig tool in the Command Prompt.

2.  

5

Look for Physical Address. This your MAC address.

Method 2 : Using Any Version of Windows

1. Open the command prompt. Press the ⌘ Win+R keys and type cmd into the Run field. Press ⌅ Enter to start the Command Prompt.

• In Windows 8, press ⌘ Win+X and select Command Prompt from the menu.

2. Run IPConfig. At the command prompt, type ipconfig /all and press ⌅ Enter. This will display configuration information for all of your network connections.

* Look for Physical Address. This is another way to describe your MAC address. Make sure you get the physical address of the correct network adapter - usually there are several listed. For example, your wireless connection will have a different MAC address than your Ethernet connection.^[1]

Method 3 : Using Windows XP, Vista, 7, 8 or 8.1

1. Open the command prompt. Press the ⌘ Win+R keys and type cmd into the Run field. Press ⌅ Enter to start the Command Prompt.

• In Windows 8, press ⌘ Win+X and select Command Prompt from the menu.

* Run GetMAC. At the command prompt, type getmac /v /fo list and press ⌅ Enter. This will display configuration information for all of your network connections.

* Look for Physical Address. This is another way to describe your MAC address. Make sure you get the physical address of the correct network adapter - usually there are several listed. For example, your wireless connection will have a different MAC address than your Ethernet connection.

Method 4: Using Windows 98 and XP

* Connect to a network. This method is only applicable if you are currently connected. Make sure to connect with the interface that you need the MAC address for (Wi-Fi is you you’re your wireless card’s MAC address, Ethernet if you need your wired card’s MAC address).

*Open Network Connections. If you don’t have a desktop icon for this, find the connection icon in the taskbar (the lower right-hand corner of the Windows toolbar) and click on it to either bring up your current connection or a list of available networks.

*You can also access Network Connections from the Control Panel, located in the Start menu.

*Right-click your connection and select Status.

*Click Details. Note that, in some versions of Windows, this may be under the Support tab. This will open a list of configuration information about the connection, similar to what appears when you use the IPConfig tool in the Command Prompt.

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Domain controller could not contact error at  logon message troubleshooting:

• Ensure the domain name is typed correctly.
• Check preferred domain Ip address is added.
• Check lan cable connectivity between router/switch to computer.
• If it is new account make sure group policy settings is updated. You can type gpupdate /force at Domain controller (Server).
• Sometimes old accounts password gets expire, so you need to reset the password and check.
• However, if its wireless or wire line connection using DHCP ip, then follow the steps given below:

Login using local account, Run IPCONFIG /RELEASE & IPCONFIG /RENEW in computer and check.

How to troubleshooting network connectivity issues?

Typical Symptoms

*Unable to connect to the router

*Intermittently disconnects from the network (internet)

*Weak wireless connection

*Page not displayed on web page

*Unable to connect to Internet

Notes :  Make sure the computer does not have two anti-virus or two firewalls installed. If you are using the Windows firewall, disable the McAfee firewall or vice-versa.

If your web browser home page changed without your permission, reference the Detecting/Identifying Spyware and Detecting/Identifying Viruses checklists.

Required first steps

Network equipment

*Make sure the DSL/cable modem and router are properly connected and functioning.

*Make sure the DSL/cable modem and router LEDs are lit.

*Make sure the cables to the DSL/cable modem and router are connected correctly.

*Make sure a network cable is being used and not a telephone cable.

If given a choice between using Ethernet or USB to connect the modem to the router or directly to the computer, use Ethernet for better connection and reliability.

Reseat network cables

*Remove and reinstall the network (RJ-45) cable between the router and the cable/DSL modem.

*Ipconfig release/renew sequence

*Complete an ipconfig release/renew sequence. After the default gateway repopulates, *wait 30 seconds and reconnect.

*From the Start menu, click Run.

In the Run dialog box, type: cmd. Press ENTER.

At the command prompt, type: ipconfig /release. Press ENTER. The information should appear without the default gateway being populated.

At the command prompt, type: ipconfig /renew. The information should appear after a few seconds with the default gateway repopulated. Write down the number for the default gateway.

Next steps

• For wireless networks, continue with the steps in the Wireless Steps section. Continue on with the steps in Wired & Wireless Steps and Internet Connection Steps until the issue is resolved.
• For wired networks, start with Wired & Wireless Steps. Continue on with the steps in Internet Connection Steps until the issue is resolved.
• If you are not using a network for sharing the Internet, or the network connection is functioning properly, go to the Internet Connection Steps.

Wireless Steps

Turn on the wireless antenna radio

If the computer is a notebook using the integrated wireless adapter, make sure that the wireless antenna radio is turned on. Most Gateway notebooks have a designated multi-function button or function key to turn your wireless antenna on or off. This information is located in your notebook's user guide.

• Gateway 200ARC - Multi-function button (last on right)
• Gateway M275 - keyboard keys Fn+F7
• Gateway M505 - Multi-function button (first on top)
• Gateway M500 - Multi-function button (first on top)
• Gateway M675 - Multi-function button (last on right)
• Most other Gateway and eMachines notebooks - keyboard keys Fn+F2

For notebooks equipped with a Wireless network switch on the chassis, ensure this switch is in the On position. The switch must be turned on for the wireless LAN and Bluetooth function keys to work (Fn+F2 for wireless and Fn+F6 for Bluetooth). Reference the Product pages for specific model information.

Check the router location

Make sure that the computer is in the same room or very close to where the wireless router or access point is located.

Check the SSID

Make sure that the SSID (network name) is turned on at the wireless router. For network security, it is best to not use the default name for the SSID.

A simple method to enter the router configuration is using the Default Gateway in the Internet Explorer address bar.

7.                  From the Start menu, click Run.

8.                  In the Run dialog box, type: cmd, then press ENTER.

9.                  At the command prompt, type: ipconfig, then press ENTER.

10.              Document the IP address for Default Gateway.

11.              Open Internet Explorer. Enter the Default Gateway IP address in the Internet Explorer address bar, then press ENTER.

12.              Enter the User Name and Password when prompted.

13.              On the menu, locate Wireless Settings (name may vary), then verify the SSID broadcast is enabled.

Note: The procedure to turn on the SSID varies from router to router. Check the router documentation or manufacturer's website for information on performing this step.

Connect to correct wireless router

Make sure you are attempting to connect to the correct router and not your neighbor's wireless network. Having a unique SSID makes this easier. Reference the router documentation for more details.

14.              Click Start, click Control Panel, click Network and Internet Connections,
View Picture

15.              In Network and Internet Connections, click Network Connections.

16.              Right-click on the Wireless Network Connection.

17.              From the menu, select View Available Wireless Networks.

18.              From the list of wireless networks, select the desired network, then click Connect.

Check for wireless network encryption

* Make sure the encryption code is entered correctly if the router has encryption enabled. The encryption code (passphrase) is prompted for when first attempting to connect to the selected network when the network is encrypted.

* Temporarily disable encryption on the wireless router, then try to connect to the router. If the computer connects without encryption, write down the encryption code entered verbatim (it is case sensitive), then retry with encryption enabled.

Note: The procedure to enable and disable encryption varies from router to router. Check the router documentation or manufacturer's website for information on performing this step.

Recognize network

See if the adapter can recognize a different network than the one desired. If the adapter can detect a different network, there may be a problem with the router/access point or it's settings.

Check the Power Savings setting

If this is a notebook computer, check power consumption settings for when the computer is running on battery power.

*Open Device Manager and locate the wireless NIC.

*Double-click the wireless NIC entry to open properties.

*In the Properties dialog box, click the Power Management tab.

*Look through the various options on this page to see if there is anything related to Power Save settings. If so, try increasing this to a higher value. If the option is just a check mark, remove the check mark so Windows is not allowed to turn off the wireless card.
Note: The actual setting varies between different models, reference the Product pages for the specific model.

Save changes, and then reboot and test.

Check the internal PCI wireless adapter

If the computer is a desktop with an internal PCI wireless adapter, make sure the card is physically installed correctly. Make sure the antenna is connected to the card. The antenna for a 802.11/b or 802.11/g is typically a single antenna. The antenna for the 802.11/n card typically has three cables that connect to the card.

Check the wireless standard

Make sure that the adapter and wireless router are using the same standard (802.11a/b/g).

Check for environmental interferences

Check for environmental interferences like cordless telephones or microwaves using the same frequency. Fluorescent lights and other items that create an electromagnetic field can also interfere with signal reception.
There are things you can try in this situation:

*If any devices like these are near your computer, turn them off temporarily or move them farther away.

*Change the router or access point settings to use a different wireless channel, or set the channel to be selected automatically if it is set to a fixed channel number. Sometimes one wireless channel is clearer than others. In the United States and Canada, you can use channels 1, 6, and 11. Check the information that came with your access point or router for instructions about setting the wireless signal channel.

*Move the location of the wireless router or location of the computer to where the interfering items do not affect signal reception.

Wired & Wireless Steps

Disable Proxy setting

1. In Internet Explorer, click Tools, then click Internet Options.
2. In Internet Options, click the Connections tab.
3. Click the LAN settings button.
4. In the Proxy server section, make sure the check mark is removed for the box Use a proxy server for your LAN.
5. Click OK twice.

Use ping

Use the ping command to send test packets to an address to test functionality.

6. Click Start, then click Run.
7. In the Run dialog box, type cmd, then click OK.
8. At the command prompt, type ipconfig and press ENTER.
9. Write down the information listed for IP Address (local address) and Default Gateway (router's address).
10. At the command prompt, type ping xxxx (where xxxx is the address or entry listed in the table below).
11. Use the steps in the following table in order to troubleshoot the problem. If the step completes successfully, move to the next step.

·  Action		What it tests	What it does not test
1	Ping 127.0.0.1 (Loopback address)	Pinging the loopback tests the TCP/IP stack and software. A network card is not required to ping the loopback. If the notebook fails the loopback test: If pinging the loopback fails, Reset the TCP/IP protocol. After resetting the TCP/IP protocol, ping the loopback address again. If it fails again, reload the computer using Full Factory Recovery procedures.	A successful ping of the loopback address does not prove that the network card is working. The network hardware is never used to ping the loopback.
2	Ping the local address (Computer's IP address)	Pinging the computers address tests the card's software and internal hardware, as well as the TCP/IP and the driver. If pinging the local address fails, power down the computer and reseat the network card (if add-in card). Power on the computer and ping the local address again. If pinging the local address fails again, or if the network card is integrated, reload the network card driver, then ping the local address again. If pinging the local address still fails, replace the add-in network card. Follow proper service procedures if the "network card" is integrated.	Since the ping is local, the network connector and cable are not tested.
3	Ping the Default Gateway	Pinging the computer's Default Gateway tests the network hardware and an external connection. A successful ping of the Default Gateway proves the network hardware is functioning correctly. If pinging the Default Gateway fails, then there is no connection to the router or modem, whichever is handing out the TCP/IP addresses. Reseat network cables connections and ping the address again. If ping fails again, conference router/modem manufacturer.	Pinging the Default Gateway does not test external connections or other segments of the network.
4	Ping 64.233.167.104 (Google.com IP address)	Pinging the IP address of an external site tests the computer's ability to access external systems or sites. All domain names, such as Gateway.com, have a corresponding IP address that's translated by DNS. If pinging the IP address fails, check broadband Internet service service.	Pinging an IP address does not test a DNS address. If the DNS resolver is corrupted, or the DNS server is down, a ping may work and opening a web page would still fail.
5	Ping www.google.com (google.com DNS name)	Pinging the domain name of an external site tests that the card is working and that the computer has a valid IP and DNS address. If pinging the domain name fails, refer to Ipconfig /flushdns.	If the service provider is having problems with a specific region, some sites may work while others fail.

ipconfig /flushdns

Complete an ipconfig /flushdns process. After the default gateway repopulates, wait 30 seconds and reconnect.

1. From the Start menu, click Run.
2. In the Run dialog box, type: cmd. Press ENTER.
3. At the command prompt, type: ipconfig /flushdns. Press ENTER.

Reset the TCP/IP protocol

4. Click Start, then click Run.
5. In the Run dialog box, type: cmd, then click OK.
   
   
6. Type: netsh int ip reset resetlog.txt, then press ENTER.
   Type: Exit, then press ENTER.
   Restart the computer.

Note: After resetting the TCP/IP protocol, ping the loopback address. If pinging the loopback address fails after the reset, reload the computer using Full Factory Recovery procedures.

Power-cycle network components

* Disconnect the power, wait one minute, then reconnect power to the DSL/Cable modem. This power-cycles (restarts) the DSL/Cable modem. Make sure proper LEDs light on the DSL/Cable modem.

* Disconnect the power, wait 15 seconds, then reconnect power to the router. This power-cycles the router. Make sure proper LEDs light on the router.

* Restart the computer. For notebooks using a PC card adapter, reseat the card prior to restarting the notebook.

*Retry connection.

Note: If you are able to use your telephone over VOIP, the internet connection to the modem is active. Do not power-cycle the modem as the internet connection is working.

Check Device Manager

Make sure that the network adapter has the correct driver and is working properly in Device Manager.
The following is an example of Intel Pro/Wireless Adapter Properties showing the adapter is working properly message on the General tab.
If the adapter is detected as not working properly, uninstall and reinstall the drivers following instructions in the Windows XP Device Driver Checklist.

Update the device driver

Remove and then re-install the driver for the wireless adapter.

Open Device Manager. Locate the Network Adapters entry, and then expand it by clicking the plus (+) symbol in front of it.

Select the entry for the wireless adapter. Right-click the entry, and then from the menu select Uninstall.

From the Action menu, click Scan for hardware changes.

Windows redetects the wireless adapter and installs the appropriate device drivers.

 

Start into Windows using Safe Mode with Networking

* Restart the computer.

* As the Gateway/eMachine logo appears, start tapping the F8 key repeatedly until the Advanced Options Menu appears.

Note: If the Windows logo comes up or the computer enters normal Windows again, restart the computer and retry.

* Use the arrow keys to highlight Safe Mode with Networking, then press the ENTER key.

* If prompted for the operating system, select the correct option, then press ENTER.

* If prompted for a username, select the correct user's name and enter the password.

* Upon entering Windows, you are prompted whether to continue using Safe Mode. Select Yes.

* Open Internet Explorer. Type www.gateway.com in the address bar to test the Internet connection.

* If able to access the internet, restart computer and remove startup items using System Configuration (MSConfig). Re-enable items one at a time and restart the computer, then test the connection each time.

Reset router to factory defaults

g.                  Reset the router to factory defaults. This is normally a small button on the front or rear of the router.

h.                  Restart the computer.

i.                    Retest your connection.

Note: Any custom setting on the router can be re-entered after resetting the router and testing the connection. An incorrect setting can prevent connection.
Note: The procedure to reset the router varies between manufacturers. Check the router documentation or manufacturer's website for information on performing this step.

Check DHCP

Check if the router and the cable/DSL modem are both using DHCP. Disable DHCP on the router if both are using it.
Note: The procedure to change the router settings varies between manufacturers. Check the router documentation or manufacturer's website for information on performing this step.

Check IP address

Check if the router and the cable/DSL modem are using the same IP address. Change the IP address on the router if both are using the same address.
Note: The procedure to change the router settings varies between manufacturers. Check the router documentation or manufacturer's website for information on performing this step.

Run System Restore

 

Internet steps

Restart after downloading updates

If updates for Windows or security software have been downloaded since the last time the computer was started (or restarted), restart the computer to have the changes take effect.

Secure Sites

Check to see if it is a secure site being accessed. This is usually noted by an address beginning with https:// or states that you are accessing a secure site when clicked on.

For problems with secure sites, reference the Help Accessing Secure Internet Sites checklist.

Check Proxy setting in Internet Explorer

Make sure that the selection for Use Proxy is not enabled.

1. In Internet Explorer, click Tools, then click Internet Options.
2. In Internet Options, click the Connections tab, then click the Settings button.
3. In the Proxy server section, make sure there is not a check in box for Use a proxy server.... If one is present, remove the check mark, then click OK.
4. Close Internet Options, then close Internet Explorer.
5. Restart the computer, then retry the Internet connection.

Delete cookie files

6. Open Internet Explorer.
7. From the Tools menu, click Internet Options.
8. In the Internet Options dialog box, click Delete Cookies.
9. In the Delete Cookies dialog box, click OK.

Delete temporary internet files

10. Open Internet Explorer.
11. From the Tools menu, click Internet Options.
12. In the Internet Options dialog box, click Delete Files.
13. In the Delete Files dialog box, click to select Delete all Offline Content, and then click OK.

Delete downloaded program files

1. Open Internet Explorer.
2. Click Tools, and then click Internet Options.
3. Click Settings.
4. Click View Objects.
5. Click View, and then click Details.
6. If damaged appears in the Status column for any program file, remove that program file.
7. Close the Downloaded Program Files dialog box.

Reset Internet Explorer to default settings

8. In Internet Explorer, click Tools, and then click Internet Options.
   
   
9. Click the Advanced tab, and then click Restore Defaults.
   Internet Explorer settings are reset. When completed, click OK.
   Close Internet Explorer.
10. Re-open Internet Explorer, and then try to browse the Internet.

Check for DSL filters

If you are using a DSL modem for your ISP connection, make sure filters are on every telephone jack other than the one where the modem is connected. This includes jacks being used for satellite service.

Check broadband internet service

Make sure the broadband Internet service is active by temporarily connecting the computer directly to the DSL/cable modem, using an RJ45 cable. If the Internet connection is not functional, troubleshoot Internet connectivity.

If necessary, conference in with the Internet Service Provider.

Note: If the DSL/cable modem has been replaced and not registered, contacting the ISP is necessary.

The following is a list of common Internet Service Provider.