Offical Network Connectivity Troubleshooting Technique Thread

Discussion in 'Networking & Internet' started by Jason, Feb 1, 2008.

  1. Jason

    Jason

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    Below are some of the many tools available to you built into Vista in order to help you figure out your problem. I suggest trying them, watching the effect and if it does not help make sure to bring it back to its original state.



    Update your NIC drivers or rollback:

    Many times windows update will install a newer driver which causes problems with your existing card. Something reverting back to the Microsoft driver will fix the problem rather then using the Manufacturer Vista drive. The opposite can also be true.



    How to assign static IP's in Vista:

    Go to you "Network and Sharing Center" on left side click "Manage Network Connections" then right click the appropriate connection and hit "Properties". Under the properties of TCP/IPv4 or v6, you enable DHCP and select Alternative Configuration. then add static IP address. You can assign static IP address and then select Advanced to assign additional IP addresses.



    Disabling Auto-Tuning:

    Vista introduces a new feature called “Receive Window Auto-Tuning”. What it does is to adjust the receive windows size continually based upon the changing network conditions. You can see this article if you are interested in details.



    Some people report that auto-tuning can cause network time out problems with specific applications and routers. You can turn it off by:



    1. Open up an elevated command prompt.

    2. Enter the following command to disable auto-tuning

    netsh interface tcp set global autotuninglevel=disabled



    If you found that this doesn’t fix your problem, you can turn it back on.



    1. Open up an elevated command prompt.

    2. Enter the following command to enable auto-tuning

    netsh interface tcp set global autotuninglevel=normal



    You can use this command to view the states of the TCP global paremeters.



    netsh interface tcp show global.



    This command is also known to correct problems for people who cannot access HTTPS sites using IE7 in Vista, and logon problems with various messenger applications.



    How to Disable TCP/IP V6

    Navigate: Start>Network>Network and Sharing Center>Manage Network Connections. Open the properties of the connection. Uncheck TCP/IPv6.



    Can't receive IP from a DHCP Server

    Symptom: A Vista is setup to obtain an IP address from a DHCP. However the Vista cannot receive an IP address from the DHCP. If you assign static Vista, you can access other remote computers and the Internet.



    Solution: To resolve this issue, disable the DHCP BROADCAST flag in Windows Vista. To do this, please follow these steps:

    1. Run regedit from the Vista.



    2. Open the following registry subkey:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{GUID}

    In this registry path, click the (GUID) subkey that corresponds to the network adapter that is connected to the network.

    3. On the Edit menu, point to New, and then click DWORD (32-bit) Value.

    4. In the New Value box, type DhcpConnDisableBcastFlagToggle, and then press ENTER.

    5. Right-click DhcpConnDisableBcastFlagToggle, and then click Modify.

    6. In the Value data box, type 1, and then click OK.

    7. Close Registry Editor.



    The 0.0.0.0 gateway problem resulting in limited connectivity:

    This is a problem I had recently after having problems w/ my router. Open the command prompt and be sure to right click it and hit "Run as Administrator" then type IPconfig /all. Your results will look something like this for each network adapter you have installed:



    Physical Address. . . . . . . . . : 00-18-F8-29-BF-52

    DHCP Enabled. . . . . . . . . . . : Yes

    Autoconfiguration Enabled . . . . : Yes

    Link-local IPv6 Address . . . . . : fe80::b1b6:632f:6a0b:57ee%8(Preferred)

    IPv4 Address. . . . . . . . . . . : 192.168.1.100(Preferred)

    Subnet Mask . . . . . . . . . . . : 255.255.255.0

    Lease
     
    Jason, Feb 1, 2008
    #1
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