Cannot access shares on PC that is connected by wireless

I've encountered a strange problem.

A network of three PCs, all connected wirelessly, cannot access shared
drives on one of the PCs - but only if that "sharing" PC is connected by
wireless; if I connect it by Ethernet it works fine. All PCs get their IP
addresses by DHCP.

I've tested with the router in the same room as the PCs (which is not where
it normally lives) to eliminate weak signal.

All PCs are XP Home SP2.

Let's call the "sharing" PC "A" and the two laptops "B" and "C".

PC "A" has a Belkin PCI card which worked fine to an old 3 Com router; the
problems started when I replaced that router with a Netgear DG834N because
the 3 Com's ADSL modem had failed. "A" can access the internet fine (HTTP,
POP3 etc).

Although all the PCs can ping each other by IP address, "B" and "C" cannot
ping "A" by hostname (the name resolution is failing) although "B" and "C"
can ping each other by hostname and can also see each other's shares (if I
create shares on them for testing purposes) using "net view \\B". Because
the name resolution is failing, "net view \\A" and mapped drives which refer
to "A" by name also fail when executed on "B" and "C".

As soon as I disable A's wireless adaptor and connect it to the router by
Ethernet, "B" and "C" can ping it and see its shares.

I'm going to try with a Netgear adaptor (probably a WG111 USB device so I
can position the aerial higher than on the floor at the back of the PC,
given that signal strength is not brilliant when the router is in its normal
position) as oposed to the Belkin card.

Is there anything else I can try to diagnose/fix the problem?

On other thing I noticed. I have a utility NetScan which pings all IPs in a
subnet and then resolves names, shares and MAC addresses. Although an
explicit ping of A's IP address (from the command prompt on B or C)
succeeds, running NetScan doesn't list A if it is connected wirelessly
whereas it does if A is connected by cable: it doesn't even locate the IP
address, never mind resolve the corresponding hostname and shares.

"Martin Underwood" <a@b> wrote in message
news:465344e6$0$8754$(E-Mail Removed)...
> I've encountered a strange problem.
>
> A network of three PCs, all connected wirelessly, cannot access shared
> drives on one of the PCs - but only if that "sharing" PC is connected by
> wireless; if I connect it by Ethernet it works fine. All PCs get their IP
> addresses by DHCP.
>
<snip problem>

Bloomin hell its normally us asking for your help.

Well as you've been a help to me I'll have a goole around see if I come
up with anything.

On Tue, 22 May 2007 20:29:57 +0100, "Martin Underwood" <a@b> mused:

>I've encountered a strange problem.
>
>A network of three PCs, all connected wirelessly, cannot access shared
>drives on one of the PCs - but only if that "sharing" PC is connected by
>wireless; if I connect it by Ethernet it works fine. All PCs get their IP
>addresses by DHCP.
>
>I've tested with the router in the same room as the PCs (which is not where
>it normally lives) to eliminate weak signal.
>
>All PCs are XP Home SP2.
>
>Let's call the "sharing" PC "A" and the two laptops "B" and "C".
>
>PC "A" has a Belkin PCI card which worked fine to an old 3 Com router; the
>problems started when I replaced that router with a Netgear DG834N because
>the 3 Com's ADSL modem had failed. "A" can access the internet fine (HTTP,
>POP3 etc).
>
>Although all the PCs can ping each other by IP address, "B" and "C" cannot
>ping "A" by hostname (the name resolution is failing) although "B" and "C"
>can ping each other by hostname and can also see each other's shares (if I
>create shares on them for testing purposes) using "net view \\B". Because
>the name resolution is failing, "net view \\A" and mapped drives which refer
>to "A" by name also fail when executed on "B" and "C".
>
>As soon as I disable A's wireless adaptor and connect it to the router by
>Ethernet, "B" and "C" can ping it and see its shares.
>
>I'm going to try with a Netgear adaptor (probably a WG111 USB device so I
>can position the aerial higher than on the floor at the back of the PC,
>given that signal strength is not brilliant when the router is in its normal
>position) as oposed to the Belkin card.
>
>Is there anything else I can try to diagnose/fix the problem?
>
>On other thing I noticed. I have a utility NetScan which pings all IPs in a
>subnet and then resolves names, shares and MAC addresses. Although an
>explicit ping of A's IP address (from the command prompt on B or C)
>succeeds, running NetScan doesn't list A if it is connected wirelessly
>whereas it does if A is connected by cable: it doesn't even locate the IP
>address, never mind resolve the corresponding hostname and shares.
>
Router blocking traffic between wireless and LAN? I used to have a
router did this, ended up sticking a WAP on the LAN instead.
--
Regards,
Stuart.

Lurch wrote in message
(E-Mail Removed):

> On Tue, 22 May 2007 20:29:57 +0100, "Martin Underwood" <a@b> mused:
>
>> I've encountered a strange problem.
>>
>> A network of three PCs, all connected wirelessly, cannot access
>> shared drives on one of the PCs - but only if that "sharing" PC is
>> connected by wireless; if I connect it by Ethernet it works fine.
>> All PCs get their IP addresses by DHCP.
>>
> Router blocking traffic between wireless and LAN? I used to have a
> router did this, ended up sticking a WAP on the LAN instead.

Except that two of the three PCs can communicate wirelessly with each other
but con't communicate wirelessly with the third. If *any* two PCs can
communicate wirelessly, that suggests that Wireless Isolation is turned off.
And before anyone suggests it, there's no MAC filtering defined - if there
was, that would prevent the named PCs from connecting at all.

Unfortunately the router will be situated remotely from all the PCs, so any
solution which involves cabling some PCs won't work. Having said that, the
wireless reception is a bit low at the best of times, even though it's only
about 50 metres from a first-floor room to a garden shed across a
driveway/yard, and a large van that parked on the driveway killed the
signal. So I'm wondering whether it's feasable to use wireless even over
this short distance. If it turns out not to be, the router will have to go
in the shed (and so could be cabled to the misbehaving PC) and a phone line
will have to upgraded to a broadband and phone line, duplicating the
broadband that's used in the house, which would increase the customer's
running costs and meaning there wasn't seamless coverage in office (the
shed) and house.

On Tue, 22 May 2007 22:15:23 +0100, "Martin Underwood" <a@b> mused:

>Lurch wrote in message
>(E-Mail Removed):
>
>> On Tue, 22 May 2007 20:29:57 +0100, "Martin Underwood" <a@b> mused:
>>
>>> I've encountered a strange problem.
>>>
>>> A network of three PCs, all connected wirelessly, cannot access
>>> shared drives on one of the PCs - but only if that "sharing" PC is
>>> connected by wireless; if I connect it by Ethernet it works fine.
>>> All PCs get their IP addresses by DHCP.
>>>
>> Router blocking traffic between wireless and LAN? I used to have a
>> router did this, ended up sticking a WAP on the LAN instead.
>
>Except that two of the three PCs can communicate wirelessly with each other
>but con't communicate wirelessly with the third. If *any* two PCs can
>communicate wirelessly, that suggests that Wireless Isolation is turned off.
>And before anyone suggests it, there's no MAC filtering defined - if there
>was, that would prevent the named PCs from connecting at all.
>
Oops, missed that bit.

>Unfortunately the router will be situated remotely from all the PCs, so any
>solution which involves cabling some PCs won't work. Having said that, the
>wireless reception is a bit low at the best of times, even though it's only
>about 50 metres from a first-floor room to a garden shed across a
>driveway/yard, and a large van that parked on the driveway killed the
>signal. So I'm wondering whether it's feasable to use wireless even over
>this short distance. If it turns out not to be, the router will have to go
>in the shed (and so could be cabled to the misbehaving PC) and a phone line
>will have to upgraded to a broadband and phone line, duplicating the
>broadband that's used in the house, which would increase the customer's
>running costs and meaning there wasn't seamless coverage in office (the
>shed) and house.
>
I wouldn't go to the lengths of new lines and DSL services, worst case
(if you can't run wires, which I'd be surprised if it wasn't possible)
is wireless access points set as repeaters\bridges and\or directional
antennae. Cheaper than line rental and DSL for a year.
--
Regards,
Stuart.

Lurch wrote in message
(E-Mail Removed):

> On Tue, 22 May 2007 22:15:23 +0100, "Martin Underwood" <a@b> mused:
>
> I wouldn't go to the lengths of new lines and DSL services, worst case
> (if you can't run wires, which I'd be surprised if it wasn't possible)
> is wireless access points set as repeaters\bridges and\or directional
> antennae. Cheaper than line rental and DSL for a year.

Overhead or underground wires aren't an option, the customer says. I did
wonder about using homeplug devices, but the shed is powered from a separate
feed from the one to the house - who knows, it may even turn out to be a
different phase ;-)

The wireless access points with directional aerials solution ought to work.
Even then there may be problems if a van or 4x4 (both the people who work
there have 4x4s) parks in the way, unless the house aerial can be mounted on
the eaves and the shed aerial can be mounted on the roof. Talk about a
hostile environment!

In article <46535e49$0$8719$(E-Mail Removed)>,
Martin Underwood says...
> Lurch wrote in message
> (E-Mail Removed):
>
> > On Tue, 22 May 2007 20:29:57 +0100, "Martin Underwood" <a@b> mused:
> >
> >> I've encountered a strange problem.
> >>
> >> A network of three PCs, all connected wirelessly, cannot access
> >> shared drives on one of the PCs - but only if that "sharing" PC is
> >> connected by wireless; if I connect it by Ethernet it works fine.
> >> All PCs get their IP addresses by DHCP.
> >>
> > Router blocking traffic between wireless and LAN? I used to have a
> > router did this, ended up sticking a WAP on the LAN instead.
>
> Except that two of the three PCs can communicate wirelessly with each other
> but con't communicate wirelessly with the third. If *any* two PCs can
> communicate wirelessly, that suggests that Wireless Isolation is turned off.
> And before anyone suggests it, there's no MAC filtering defined - if there
> was, that would prevent the named PCs from connecting at all.

OK..Assuming you've made sure file and print sharing is listed in the
exceptions of the firewall you have.

Network Connections. Right click on the wifi one and select Properties.
Click on TCP/IP protocol and select properties. At the bottom right
under entries for IP/DNS, click Advanced. Go to the WINS tab. Click the
radio button marked "Enable NetBIOS over TCP/IP".



--
Conor

Light travels faster than sound. This is why some people appear bright
until you hear them speak.........

Conor wrote in message
(E-Mail Removed):

> In article <46535e49$0$8719$(E-Mail Removed)>,
> Martin Underwood says...
>> Lurch wrote in message
>> (E-Mail Removed):
>>
>>> On Tue, 22 May 2007 20:29:57 +0100, "Martin Underwood" <a@b> mused:
>>>
>>>> I've encountered a strange problem.
>>>>
>>>> A network of three PCs, all connected wirelessly, cannot access
>>>> shared drives on one of the PCs - but only if that "sharing" PC is
>>>> connected by wireless; if I connect it by Ethernet it works fine.
>>>> All PCs get their IP addresses by DHCP.
>>>>
>>> Router blocking traffic between wireless and LAN? I used to have a
>>> router did this, ended up sticking a WAP on the LAN instead.
>>
>> Except that two of the three PCs can communicate wirelessly with
>> each other but can't communicate wirelessly with the third. If *any*
>> two PCs can communicate wirelessly, that suggests that Wireless
>> Isolation is turned off. And before anyone suggests it, there's no
>> MAC filtering defined - if there was, that would prevent the named
>> PCs from connecting at all.
>
> OK..Assuming you've made sure file and print sharing is listed in the
> exceptions of the firewall you have.

It's Norton Internet Security 2007. I disabled the firewall as part of my
testing, but to no avail. For some reason I found that it was not sufficient
to trust "all computers on the network with MAC address X" [that of the
router] but instead had to explicitly add each likely IP address
individually. Older versions of Norton (eg 2006 and before) were so much
easier in that they allowed you to add range of IP addresses to the Trusted
list.

> Network Connections. Right click on the wifi one and select
> Properties. Click on TCP/IP protocol and select properties. At the
> bottom right under entries for IP/DNS, click Advanced. Go to the WINS
> tab. Click the radio button marked "Enable NetBIOS over TCP/IP".

Ah, the NB over TCP setting - forgot to check that one! Damn! I wonder...
However I'm sure I did an "nbtstat -n" and found the entries that I'd
expect: hostname with null and space in 16th byte; workgroup name with null,
0x1D and 0x1E in 16th byte. That suggests that TCP NB is running. But I'll
check.

Strange that the same connection object (ie for the wireless card) worked
for connection to the old router.

I noticed something else: the router's "Attached Devices" page was either
empty or only listed one PC (my own laptop, used for testing) when it should
give a full DHCP client list - with computer names either shown as "Unknown"
or else as the actual hostname. My DG834GT always lists all PCs that are
connected. I was using the Windows Zero Config service to control the
wireless card, as I found it to be more resilient to temporary dropouts than
the Belkin software.

Is it likely that a change of wireless card will help (eg to a Netgear
WG111, same manufacturer as router) or is that a complete red herring? In
people's experience, is the sensitivity of a USB device, positioned higher
where it's not shielded by the PC's case, likely to be better than a PCI
card with its own stub aerial? I believe that PCI cards are supposed to be
better if you compare against USB *in the same location* but the USB device
can be positioned away from the PC's shadow.


I'd love to know what's causing such poor wireless reception. Distance is
about 50 metres, from first-floor wooden window frame and window to ground
floor wooden shed with (as far as I can tell) no foil lining to the inner
skin of the walls. There is a large metal tank along the *side* of the shed,
but not in direct line of sight for most of the shed.

Soni tempori elseu romani yeof helsforo nisson ol sefini ill des Wed, 23 May
2007 11:55:05 +0100, sefini jorgo geanyet des mani yeof do
uk.comp.home-networking, yawatina tan reek esk "Martin Underwood" <a@b> fornis
do marikano es bono tan el:

>I'd love to know what's causing such poor wireless reception.

Ley lines.

We have an area at work between two buildings. It's 10m, maximum. With a WAP
mounted on the side of one (not even indoors), and a PDA recording the signal,
we get about halfway to the other building and the signal strength is 75-80%.
One single step further, and it's gone. Completely.

You can't get a mobile phone signal in that spot either. There are no power
lines (not even underground as far as we can tell) in that spot, nor anything
else that we could see causing the drop-out. So we put it down to ley lines
and ran a fibre instead.

deKay
--
Lofi Gaming - http://lofi-gaming.org.uk
Gaming Diary - http://lofi-gaming.org.uk/diary
Blog - http://lofi-gaming.org.uk/blog
My computer runs at 3.5MHz and I'm proud of that

"Lurch" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On Tue, 22 May 2007 20:29:57 +0100, "Martin Underwood" <a@b> mused:
>
>>I've encountered a strange problem.
>>
>>A network of three PCs, all connected wirelessly, cannot access shared
>>drives on one of the PCs - but only if that "sharing" PC is connected by
>>wireless; if I connect it by Ethernet it works fine. All PCs get their IP
>>addresses by DHCP.
>>
>>Although all the PCs can ping each other by IP address, "B" and "C" cannot
>>ping "A" by hostname (the name resolution is failing) although "B" and "C"
>>can ping each other by hostname and can also see each other's shares (if I
>>create shares on them for testing purposes) using "net view \\B". Because
>>the name resolution is failing, "net view \\A" and mapped drives which
>>refer
>>to "A" by name also fail when executed on "B" and "C".
>>
>>As soon as I disable A's wireless adaptor and connect it to the router by
>>Ethernet, "B" and "C" can ping it and see its shares.

I discussed this problem with my local computer shop (where bought the
Belkin PCI card in the offending PC) and they said that they've had a lot of
problem with the Netgear DG834N not working properly with Wireless G devices
(either built-into laptops or PCI/PMCIA/USB plug-in devices). This is
despite Netgear's website saying that it is fully backward compatible with
Wireless G. I specifically bought the N model because it is described on PC
World's web site as having the best range, but the shop advise that an "old
fashioned" DG834G or GT might be better.