Annoying difference between "Map Network Drive" and "Net Use"

[Michael A. Covington]

Greetings,

I'm using VPN to get to a server at my office; Windows 2000 server (which I
manage) and Windows XP Home on the laptop. And I'm having the following
curious problem.

If I use "Map Network Drive" in My Computer, everything works fine. For
instance, if I map U: to \\servername\users\mc, all is well.

If I use "net use u: \\servername\users\mc" I usually get an error 53
(network path not found).

Further... as soon as I have done *one* Map Network Drive, I can *then* do
as many "net use" operations as I want (to map additional drives).

And if, without doing a Map Network Drive, I simply wait a few minutes after
connecting, then "net use" will often work.

Since "Map Network Drive" and "Net Use" are supposed to be identical, what's
going on here?

I'd like to use "Net Use" in a script that is executed automatically upon
connecting (via CMAK). That's how I discovered the problem. The
MapNetworkDrive operation in VBSCRIPT, which I also tried, apparently has
the same problem as "Net Use."

More about it:

- When I'm unable to use Net Use, I'm also unable to open paths such as
\\servername\blah\blah in a window or with Run. However, once I've done a
successful Map Network Drive, they work.

- Putting the IP address in place of servername doesn't help. Nor does
using the fully qualified path for it.

The bottom line:

- What is this superpower that "Map Network Drive" has, and how can I make
it happen automatically?

I'm guessing it has something to do with WINS or browsing.

Thanks to anyone who can shed light on this! You'll be advancing the cause
of science.

 

[Brian Oakes [MSFT]]

Help the cause of science... I can't pass that up.

My best GUESS is along the same lines are you. When you map a drive via the
gui it probably doesn't actually connect to it right then. (I haven't looked
at that in a while so I could be very wrong.)

When you map from the cmd line, it actually makes the connection to the
remote server, since you are doing it via a vpn it might be a latency or
timing issue.

if you create a local LMHOSTS files does the process speed up? That will
taken Wins name resolution out of the picture in this case. Let us know
--

Brian Oakes

This posting is provided "AS IS" with no warranties and confers no rights.
Please reply to the newsgroup so that others may benefit.

 

[Michael A. Covington]

LMHOSTS does not seem to help.

What I am thinking is roughly this:

- When I "Map Network Drive," Windows actually does something else, to
ensure NETBIOS name recognition, before mapping the drive.

- When I "Net Use..." it doesn't do the first step.

I've determined that it takes EXACTLY 30 seconds to establish the connection
if I do this:

:loop
net view \\servername
if errorlevel 1 goto loop

And I can get things working that way. That is, when the loop completes, the
connection is working properly.

Fortunately the problem has (in a roundabout way) become (partly)
irrelevant. I've discovered that if I simply "Map Network Drive" and choose
"Reconnect On Logon," then the drives reconnect when I connect to the VPN
again. So it is not actually necessary to run a script to map the drives
when the user connects.

But inquiring minds still want to know! Users are going to want to know why
their connection isn't fully functional until more than half a minute after
they establish it.


Many thanks,
Michael