Can't access network shares

[Fokke Nauta]

It could be a dodgy wifi connection.

Give us a full breakdown of your network; something like this, which is
mine.

1. Desktop computer with wireless modem-router; telephone broadband.
2. Two upstairs desktop computers with wifi dongles.
3. iPad with wifi.

Ed

P.S. There's also wifi interference to consider. My front doorbell used to
ring when a neighbour used a certain car key fob.

What we have, is:

A wired LAN, with 3 desktop computers and a server (which is also a desktop
computer in fact, as it runs on XP Pro). All computers have static IP
addresses. There is a (non-wireless) router, connected to a glass fibre
modem. There is also an Access point, with a static IP address as well. All
are connected to a switch. All NIC's, cabling and the switch are 1 Gb. We
use TCP/IP, no Netbeui.
And there is the laptop, connected by Wifi to the Access point. The laptop
used to have a static address also, but since we use it on location as well,
it's configured to receive a DHCP address. In our situation it receives an
address from the router.

Is this useful to you?

You mention "a dodgy wifi connection".
I haven't thought of that, but I will connect the laptop to our LAN by wire.
See if that makes a difference. I'll come back on this one.

Fokke

 

[Fokke Nauta]

What we have, is:

A wired LAN, with 3 desktop computers and a server (which is also a
desktop computer in fact, as it runs on XP Pro). All computers have static
IP addresses. There is a (non-wireless) router, connected to a glass fibre
modem. There is also an Access point, with a static IP address as well.
All are connected to a switch. All NIC's, cabling and the switch are 1 Gb.
We use TCP/IP, no Netbeui.
And there is the laptop, connected by Wifi to the Access point. The laptop
used to have a static address also, but since we use it on location as
well, it's configured to receive a DHCP address. In our situation it
receives an address from the router.

Is this useful to you?

You mention "a dodgy wifi connection".
I haven't thought of that, but I will connect the laptop to our LAN by
wire. See if that makes a difference. I'll come back on this one.

Fokke

Ed, you're the man. I couldn't believe this:

When I wire the laptop up to the LAN and I start the laptop, it works fine.
No problem at all. When I disconnect and use the wireless connection
instead, the problem arises. When I switch back to the wired connection, the
problem remains. Only when I restart the laptop and it is connected by wire,
it works fine. Only then. As soon as I use wireless, it's wrong and stays
wrong.
I was able to reproduce this multiple times, so it seems that we found the
culprit, the wireless network. But what next?
Is there anything I need to configure differently? Do you have any
suggestions for software on the laptop I can use to see what SSID's there
are around and on which frequency?

Fokke

 

[Fokke Nauta]

<cut>

You were right.

I wouldn't have thought of that.
But when I found out that when the laptop was wired up to the LAN and it
worked OK, I started to investigate the wireless part. I found a wireless
scanner (inSSIDer-Installer-2.0.7.0126.exe) and installed that on the
laptop. We have 802.11n on channel 11, and to my surprise there were many
others on channel 11 as well, underr which a pritty strong one. So - pretty
much interference, I think.We live in an apartment building so after all it
was not a surprise to see so many SSID's
I changed to channel 3 (to my surprise the AP then sends on channel 7 as
well). After restarting the laptop all problems were solved. Now it works
flawlessly again.

Many thanks for your help and hint. Once again, I wouldn't have thought of
this.

You can download a beer from my server if you like: www.pc3.nl/beer

Fokke

 

[Char Jackson]

<cut>

You were right.

I wouldn't have thought of that.
But when I found out that when the laptop was wired up to the LAN and it
worked OK, I started to investigate the wireless part. I found a wireless
scanner (inSSIDer-Installer-2.0.7.0126.exe) and installed that on the
laptop. We have 802.11n on channel 11, and to my surprise there were many
others on channel 11 as well, underr which a pritty strong one. So - pretty
much interference, I think.We live in an apartment building so after all it
was not a surprise to see so many SSID's
I changed to channel 3 (to my surprise the AP then sends on channel 7 as
well). After restarting the laptop all problems were solved. Now it works
flawlessly again.

Many thanks for your help and hint. Once again, I wouldn't have thought of
this.

You can download a beer from my server if you like: www.pc3.nl/beer

Fokke

The only thing I can think of is that your laptop was connecting to
one of your neighbors instead of your own access point. Naturally,
your shares wouldn't be available in that case.

Have you set a custom SSID and enabled WPA/WPA2 encryption?

 

[Fokke Nauta]

The only thing I can think of is that your laptop was connecting to
one of your neighbors instead of your own access point. Naturally,
your shares wouldn't be available in that case.

Have you set a custom SSID and enabled WPA/WPA2 encryption?

No, it definitely did not. It was our own AP with a custom SSID and with
WPA/WPA2 encryption indeed.
There was another wifi xmitter on the same previous channel, so to MHO it
was caused by interference.
The problem dissapeared after changing the AP to a different channel.
Strangely enough the problem only occurred between the laptop and the
server, not between the laptop and other XP machines.

Fokke

 

[Ed Cryer]

<cut>

You were right.

I wouldn't have thought of that.
But when I found out that when the laptop was wired up to the LAN and it
worked OK, I started to investigate the wireless part. I found a wireless
scanner (inSSIDer-Installer-2.0.7.0126.exe) and installed that on the
laptop. We have 802.11n on channel 11, and to my surprise there were many
others on channel 11 as well, underr which a pritty strong one. So - pretty
much interference, I think.We live in an apartment building so after all it
was not a surprise to see so many SSID's
I changed to channel 3 (to my surprise the AP then sends on channel 7 as
well). After restarting the laptop all problems were solved. Now it works
flawlessly again.

Many thanks for your help and hint. Once again, I wouldn't have thought of
this.

You can download a beer from my server if you like: www.pc3.nl/beer

Fokke

Ah, so the logon request was into a wireless network, not into your server.
It all makes sense now, explained under the headings of nature and
rationality.
A bit hard to pin down because of severe lack of feedback, but certainly
not supernatural as with Aquinas' herrings (?!?).

I've noticed many, many people stumble over networking problems. A
problem with a router, modem or ISP; poor info given, and they assume
it's their PC that's at fault; and then they spend ages scouring around
everything, checking settings, this that and the other.

It's hardly surprising with such very meagre feedback given. Just
imagine the different path you'd have gone down if you'd been clearly
apprised at the start that it was a logon to XXX wireless network that
you were being presented with.

Ed

 

[Fokke Nauta]

Ah, so the logon request was into a wireless network, not into your
server.
It all makes sense now, explained under the headings of nature and
rationality.
A bit hard to pin down because of severe lack of feedback, but certainly
not supernatural as with Aquinas' herrings (?!?).

I've noticed many, many people stumble over networking problems. A problem
with a router, modem or ISP; poor info given, and they assume it's their
PC that's at fault; and then they spend ages scouring around everything,
checking settings, this that and the other.

It's hardly surprising with such very meagre feedback given. Just imagine
the different path you'd have gone down if you'd been clearly apprised at
the start that it was a logon to XXX wireless network that you were being
presented with.

Ed

No Ed, the logon was for the server. The wireless network was transparent
for logging into the other machines. On the laptop I had no problem to enter
the shared directories on the other machines at all. Only with the server it
was a problem. Hitting the shared directories of the server caused a window
to pop up with the login name / password combination and whatever I tried,
it was wrong.
With the wired connection it was OK. Now I changed the xmit channel of the
AP from 11 to 3+7, it is OK as well.

So, a quite strange phenomena, isn't it?

Fokke

 

[Gene E. Bloch]

<cut>

You were right.

I wouldn't have thought of that.
But when I found out that when the laptop was wired up to the LAN and it
worked OK, I started to investigate the wireless part. I found a wireless
scanner (inSSIDer-Installer-2.0.7.0126.exe) and installed that on the
laptop. We have 802.11n on channel 11, and to my surprise there were many
others on channel 11 as well, underr which a pritty strong one. So - pretty
much interference, I think.We live in an apartment building so after all it
was not a surprise to see so many SSID's
I changed to channel 3 (to my surprise the AP then sends on channel 7 as
well). After restarting the laptop all problems were solved. Now it works
flawlessly again.

Many thanks for your help and hint. Once again, I wouldn't have thought of
this.

You can download a beer from my server if you like: www.pc3.nl/beer

Fokke

Being an opportunist, I also availed myself of your beer.

Thanks, it was very refreshing, in part because it was illicit, since I
didn't have your permission.

I am of legal age, however.

 

[Char Jackson]

No, it definitely did not. It was our own AP with a custom SSID and with
WPA/WPA2 encryption indeed.
There was another wifi xmitter on the same previous channel, so to MHO it
was caused by interference.
The problem dissapeared after changing the AP to a different channel.
Strangely enough the problem only occurred between the laptop and the
server, not between the laptop and other XP machines.

If the wireless connection continued to work while the only negative
symptom was the network shares becoming unavailable, then the problem
most certainly was not the wireless connection. Could be a
misconfigured access point, I suppose, but simple troubleshooting
would have quickly uncovered that. With so little information
available, it's hard to say what the real problem is/was.

 

[Fokke Nauta]

On Tue, 16 Aug 2011 16:04:32 +0200, "Fokke Nauta"


If the wireless connection continued to work while the only negative
symptom was the network shares becoming unavailable, then the problem
most certainly was not the wireless connection. Could be a
misconfigured access point, I suppose, but simple troubleshooting
would have quickly uncovered that. With so little information
available, it's hard to say what the real problem is/was.

It were only the network shares of the server becoming unavailable. The
shares of all the other machines on the LAN were OK.
But the server is equal to the other machines, running XP Pro, with the same
combination of user account / password.
And how could one misconfigure an AP?
It's got a fixed IP address, an Authentication mode = WPA, and WPS enabled
and a custom SSID.

And please read my previous posts. Since I changed the AP xmit channel, it
is OK. Wired was it OK as well. So?

What else information would you like to have?

I've seen many weird things coming along, but this one is new to me.

Fokke

 

[Fokke Nauta]

Being an opportunist, I also availed myself of your beer.

Thanks, it was very refreshing, in part because it was illicit, since I
didn't have your permission.

I am of legal age, however.

Well, you know where to get it now. There's plenty!
In the near future I might offer other sorts of beer
Like the Belgium Westmalle Dubble.

If you ever drink that, you don't want another beer on a sunny afternoon.

Fokke

 

[Char Jackson]

It were only the network shares of the server becoming unavailable. The
shares of all the other machines on the LAN were OK.

OK, then it definitely wasn't the wireless connection, you've
adequately proved that.

But the server is equal to the other machines, running XP Pro, with the same
combination of user account / password.
And how could one misconfigure an AP?

In any number of ways, such as configuring it to block file sharing?
Linksys, for example, has a feature called AP Isolation which would do
that. I forgot, or maybe never knew, what kind of AP you're running.
Yours may have a similar feature, or maybe you've configured other
access restrictions (port based? time based? MAC based? IP based?) and
have forgotten about it.

It's got a fixed IP address, an Authentication mode = WPA, and WPS enabled
and a custom SSID.

And please read my previous posts. Since I changed the AP xmit channel, it
is OK. Wired was it OK as well. So?

I don't know. There's only enough information to rule certain things
out and not enough information to settle on a definite cause.

What else information would you like to have?

That's ok, it seems like you 'fixed' the problem by going to a wired
connection. I just wanted to point out that your wireless connection,
or more specifically interference with your wireless connection,
wasn't involved.

I've seen many weird things coming along, but this one is new to me.

The beauty of computers is that everything happens for a reason, and
the reason can usually be found if a person is willing to throw enough
resources at it. Sometimes it's better to cut your losses and move on.

 

[Fokke Nauta]

OK, then it definitely wasn't the wireless connection, you've
adequately proved that.

Well, what actually happens, proves the opposite.
With a wired connection, there were no problems. When I changed the xmiy
channel of the AP, the problems were gone as well.
Well?

In any number of ways, such as configuring it to block file sharing? No

Linksys, for example, has a feature called AP Isolation which would do
that. I forgot, or maybe never knew, what kind of AP you're running.

Vigor AP 700

Yours may have a similar feature, or maybe you've configured other
access restrictions (port based?

No
time based?
No
MAC based?
No
IP based?)
No
and

have forgotten about it.

Excuse me, but I'm not quite a novice

I don't know. There's only enough information to rule certain things
out and not enough information to settle on a definite cause.


That's ok, it seems like you 'fixed' the problem by going to a wired
connection.

Nop. Changing the AP's xmit channel was the trick!

I just wanted to point out that your wireless connection,

or more specifically interference with your wireless connection,
wasn't involved.

I fully disagree.

The beauty of computers is that everything happens for a reason, and
the reason can usually be found if a person is willing to throw enough
resources at it. Sometimes it's better to cut your losses and move on.

And here I fully agree. Indeed, everything is pure logic and everything
happens for a reason.
Reasons we sometimes don't see and sometimes don't understand.
I don't have losses, and don't see the reasons as well, but I've seemed to
have solved my problem.

Though I still would be interested to know what was actually going on.

Fokke

 

[Char Jackson]

Well, what actually happens, proves the opposite.
With a wired connection, there were no problems. When I changed the xmiy
channel of the AP, the problems were gone as well.
Well?

But that's not true, right? I believe you said earlier that the
wireless connection allowed you to access the shares on the other
computers but not the shares on the server, thus ruling out the
wireless connection. Wireless connections run at OSI layer 2, well
below the layer where 'shares' information is located. In other words,
a wireless connection isn't smart enough to be aware of such things as
shared folders and therefore can't differentiate between shares on one
computer versus shares on another computer.

Changing the wireless channel has absolutely no relation to file
sharing. You might as well go to the kitchen and make a ham sandwich.

Vigor AP 700

No
time based?
No
MAC based?
No
IP based?)
No
and

Excuse me, but I'm not quite a novice

But I did read your previous posts. What does the WiFi channel have to
do with accessing one computer versus another on the same LAN? Besides
'nothing', of course.

The bottom line is that you made a non-related change and saw
different results, so you concluded that your change caused the new
results. It's an easy trap to fall into, or as my English teacher
probably would have said, "It's an easy trap in which to fall."

Post hoc, ergo propter hoc.

 

[Gene E. Bloch]

Well, you know where to get it now. There's plenty!
In the near future I might offer other sorts of beer
Like the Belgium Westmalle Dubble.

If you ever drink that, you don't want another beer on a sunny afternoon.

Fokke

From time to time we have a Lambic beer. The ones we find here (Silicon
Valley) are mostly flavored (Cassis, Krieke, ...), but maybe that's
normal.

We were introduced to an unflavored one at a local supermarket, but it
was too sour for us.

 

[Fokke Nauta]

The bottom line is that you made a non-related change and saw
different results, so you concluded that your change caused the new
results. It's an easy trap to fall into, or as my English teacher
probably would have said, "It's an easy trap in which to fall."

To make a long story short:

I fully agree that wifi has nothing to do with file sharing. I fully agree
that wifi lies on a lower level in the OSI model. Wireless should be totally
transparent.
I also fully agree - in first instance - that the fact that the problems
occurred with the network shares of the server only, rules out the influence
of the wireless network.

But how can you explain that the problem only occurred when using wifi? When
using a wired network, it worked flawlessly. I was able to reproduce this
multiple times. Ofcourse I tried this many times to be sure that this really
happened.
And how can you explain that after changing the AP's xmit channel to a
channel where no other wifi channels were, thus no interference, that it
works OK?

The above written is actually what happened.

I think that you forget one thing: The wifi part should be transparent but
it obviously wasn't. Most likely due to interference. How it can be
possible, against all odds, I don't know. But I was able to reproduce this
as well. Putting back the xmit channel to the previous channel, and the
problem got back again. Once again changing the channel to its new position
and the problem was gone.

Any explanation?

Fokke

 

[Fokke Nauta]

From time to time we have a Lambic beer. The ones we find here (Silicon
Valley) are mostly flavored (Cassis, Krieke, ...), but maybe that's
normal.

We were introduced to an unflavored one at a local supermarket, but it
was too sour for us.

--

I don't recognize Lambic beer. Is that Belgian import?
I know that the type of kriek beers are made with cherries. Hence the
slightly sour taste. I don't like them.
The Belgian beers, under which Duval or Westmalle, are the best. I don't
know whether they are available in the US. But I guess so.

Fokke

 

[Char Jackson]

To make a long story short:

I fully agree that wifi has nothing to do with file sharing. I fully agree
that wifi lies on a lower level in the OSI model. Wireless should be totally
transparent.
I also fully agree - in first instance - that the fact that the problems
occurred with the network shares of the server only, rules out the influence
of the wireless network.

But how can you explain that the problem only occurred when using wifi? When
using a wired network, it worked flawlessly. I was able to reproduce this
multiple times. Ofcourse I tried this many times to be sure that this really
happened.
And how can you explain that after changing the AP's xmit channel to a
channel where no other wifi channels were, thus no interference, that it
works OK?

The above written is actually what happened.

It's most likely a misconfigured access point, but there's not enough
information to reach a definitive conclusion. All I can do at this
point is rule certain things out, like wireless interference.

Try a different access point, or try a different laptop.

I think that you forget one thing: The wifi part should be transparent but
it obviously wasn't. Most likely due to interference. How it can be
possible, against all odds, I don't know. But I was able to reproduce this
as well. Putting back the xmit channel to the previous channel, and the
problem got back again. Once again changing the channel to its new position
and the problem was gone.

Any explanation?

Like I said previously, there isn't enough information available for
me to say, "This is what it is." All I can do at this point is say.
"That is not what it is."

 

[Gene E. Bloch]

I don't recognize Lambic beer. Is that Belgian import?
I know that the type of kriek beers are made with cherries. Hence the
slightly sour taste. I don't like them.
The Belgian beers, under which Duval or Westmalle, are the best. I don't
know whether they are available in the US. But I guess so.

Fokke

The lambic beers are a Belgian specialty, that even got a write-up in
Scientific American, a popular magazine here in the US for people
interested in science (and it has a number of international editions as
well).

The article was a long time ago, so I have forgotten any details.

Yes, the kriek (cherry) and the cassis (currant) are both quite sour.
That's why we don't drink them often

I've written down Duval and Westmalle for the next time I go to get beer
- thanks.

 

[Fokke Nauta]

It's most likely a misconfigured access point, but there's not enough
information to reach a definitive conclusion. All I can do at this
point is rule certain things out, like wireless interference.

Try a different access point, or try a different laptop.


Like I said previously, there isn't enough information available for
me to say, "This is what it is." All I can do at this point is say.
"That is not what it is."

The AP is certainly not misconfigured.
You forgot to - at least try to - explain why my problem was solved after I
changed the xmit channel of the AP.

I think further discussion is useless.

Fokke