JSI Tip 1745. PING works but NET USE fails?

In tip 1705, we learned that PING uses ICMP packets and may not be affected by circumstances that would cause a NET USE to a NetBIOS resource to fail.

Here are some troubleshooting steps to resolve the problem:

- If a router is between you and the resource, insure that TCP port 139 is enabled.

- If a router is between you and the resource, make sure it can pass large packet sizes. PING only send 74 bytes of data. To test for a packet size problem:

        PING <computername> -l 4048
        PING <computername> -l 3036
        PING <computername> -l 2024
        PING <computername> -l 1012

     You should NOT need to adjust the MTU,
     unless EnablePMTUDiscovery is disabled.
     You may also wish to look at EnablePMTUBHDetect.
     You can adjust the MTU at
     by adding a value name of MTU, as a type REG_DWORD,
     and setting the data value to a number between 0 and 0xFFFFFFFF.

     Datagrams larger than the Maximum Transmission Unit are divided in fragments.

- Check to make sure that the Server Service is started on the destination computer (Control Panel / Services).

- Make sure that the destination computer is not hung (it may still respond to a PING).

- Make sure that there are available licenses on the destination computer.

- Make sure that the drive letter is not already in use. Use NET USE <Drive:> /delete.

- Make sure that if a HOSTS or LMHOST file is used for name resolution, that your network is not timing out.

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