Why can't I see a computer on my network?

[Sandy]

A few weeks ago, I set up a home network using a Linksys BEFW11S4
Router. My desktop(call it A) is directly connected to the router.
I have a second desktop (call it B) connected via a Wireless PCI card
and a laptop directly connected. The laptop is for work and has a
different group name than the other two computers and can't be seen by
either computer A or computer B, which is expected..

Until recently, I could access computer B from computer A. Now I
can't. They both belong to group MSHOME. Computer B has no problem
sharing the internet connection, but if I ping computer A from it, I
get no response. WEP is enabled and I checked the encryption and it
looks correct on both ends. Boith are enabled, 64-bit, with the same
encryption key. If I check the DHCP clients table, computer A shows up
and so does the laptop, but not computer B. Also, I cannot ping
computer B from computer A.

I can't think what else to check. I can't think of what I could have
done to change the network configuration. I'm at wits end. What am I
missing?

[Paul Landregan]

"Sandy" > wrote in message
...
> A few weeks ago, I set up a home network using a Linksys BEFW11S4
> Router. My desktop(call it A) is directly connected to the router.
> I have a second desktop (call it B) connected via a Wireless PCI card
> and a laptop directly connected. The laptop is for work and has a
> different group name than the other two computers and can't be seen by
> either computer A or computer B, which is expected..
>
> Until recently, I could access computer B from computer A. Now I
> can't. They both belong to group MSHOME. Computer B has no problem
> sharing the internet connection, but if I ping computer A from it, I
> get no response. WEP is enabled and I checked the encryption and it
> looks correct on both ends. Boith are enabled, 64-bit, with the same
> encryption key. If I check the DHCP clients table, computer A shows up
> and so does the laptop, but not computer B. Also, I cannot ping
> computer B from computer A.
>
> I can't think what else to check. I can't think of what I could have
> done to change the network configuration. I'm at wits end. What am I
> missing?

If you cannot ping between computer A and B there is a layer 3 or lower
problem. Double check the WEP mode and key including the key ID I think
there's 4 to choose from for 64bit. Check the router doesn't have access
control set up if so ensure the MAC address of computer B is there.

You must find the problem at layers 2 or 3 before you try and play with the
upper layers that windows uses.

Check the subnet mask of the machines to ensure they are both on the same
network.

[Lenny Toulson]

"Sandy" > wrote in message

>
> I can't think what else to check. I can't think of what I could have
> done to change the network configuration. I'm at wits end. What am I
> missing?

Confirm that my understanding is correct: Both A and B can surf the 'Net at
the same time with no difficulties. However, neither has knowledge of each
other.

If that is correct, are you sure that B is actually using your router to
access the 'Net? You said that the DHCP client table for your router is not
showing B, but B can surf the net. The likely causes of this are: 1) B has
a static IP address or 2) B is on a different router. If B has connected to
a neighboring access point, it would be on a separate network and wouldn't
be able to ping any of your PCs.

Use the wireless network configuration tool to verify the access point in
use by your wireless card. Your configuration utility should allow you to
set the desired access point to be used. If the one in use is not yours,
set it to be yours and yours only. (Or, set it to be primarily yours, then
use the other one as backup for when yours is out. :)

If you are indeed on another access point, take this as an object lesson in
why you should secure your own wireless network. If you do not wish to
allow unfettered access to your LAN and/or Internet connection, take this
opportunity to review your security settings.

I recommend the following:
1. Disable DHCP or at least restrict the pool of IP addresses to the
specific number of PCs on your LAN.
2. Disable SSID broadcast on your access point.
3. Enable MAC address filtering using the MAC addresses of your PCs' NICs.
4. Enable encryption (WEP, but WPA is better, if available for your
devices).

These steps should be sufficient to protect most home networks from all but
very determined hackers.

And if your neighbor has an open network, why would they bother with
yours...? :)

--
Lenny

[CWatters]

"Paul Landregan" > wrote in message
...

> If you cannot ping between computer A and B there is a layer 3 or lower
> problem. Double check the WEP mode and key including the key ID I think
> there's 4 to choose from for 64bit. Check the router doesn't have access
> control set up if so ensure the MAC address of computer B is there.

I don't think this can be his problem because he said...

> Computer B has no problem sharing the internet connection.

Doesn't this imply his wireless link to the router is working OK?

But then he says..

> If I check the DHCP clients table, computer A shows up
> and so does the laptop, but not computer B. Also, I cannot ping
> computer B from computer A.

So how can B be connecting to the Internet if it isn't getting an IP address
from the router/DHCP?

It all seems a bit inconsistent, or have I missed something?

[Sandy]

On Fri, 26 Sep 2003 16:46:21 GMT, "Lenny Toulson" >
wrote:

>>Confirm that my understanding is correct: Both A and B can surf the 'Net at
>the same time with no difficulties. However, neither has knowledge of each
>other.

That is correct. Both computers can surf the net, but have no
knowledge of each other. I don't know if it matters, since as a
previous poster suggested, my problems may be below the Windows layer,
but computer A is running XP Pro and computer B is running Windows 98.
>
>If that is correct, are you sure that B is actually using your router to
>access the 'Net? You said that the DHCP client table for your router is not
>showing B, but B can surf the net. The likely causes of this are: 1) B has
>a static IP address or 2) B is on a different router. If B has connected to
>a neighboring access point, it would be on a separate network and wouldn't
>be able to ping any of your PCs.

It has to be using the router. There is no other access to the
internet. I checked the network config andit is using Dynamic IP
addressing.

>Use the wireless network configuration tool to verify the access point in
>use by your wireless card. Your configuration utility should allow you to
>set the desired access point to be used. If the one in use is not yours,
>set it to be yours and yours only. (Or, set it to be primarily yours, then
>use the other one as backup for when yours is out. :)

Okay, now you lost me. How do I determine the access point?

[wk]

From each computer browse to http://checkip.dyndns.org/

Do both of them show the same IP address? If they do then both are
connected through your router. If not, one of them is connected
through somebody else's wireless network.

wk

[Sandy]

On Fri, 26 Sep 2003 17:20:30 +0100, "Paul Landregan"
> wrote:

>>Check the subnet mask of the machines to ensure they are both on the same
>network.


Okay, that may be the problem. the subnet mask of computer A is
255.255.255.0. The subnet mask of computer B is 255.0.0.0. How to I
fix this?

[Paul Landregan]

"Sandy" > wrote in message
...
> On Fri, 26 Sep 2003 17:20:30 +0100, "Paul Landregan"
> > wrote:
>
> >>Check the subnet mask of the machines to ensure they are both on the
same
> >network.
>
>
> Okay, that may be the problem. the subnet mask of computer A is
> 255.255.255.0. The subnet mask of computer B is 255.0.0.0. How to I
> fix this?

If this has been DHCP set then your looking at two different
routers/wireless networks. Are the actual IP's similar eg 192.168.1.1 and
192.168.1.2 or totally different eg 192.168.1.1 and 10.1.1.1.

If the subnet mask is set manually then right click in network neighbourhood
to get to network properties, goto TCP/IP properties and enter the correct
Subnet mask

[Paul Landregan]

"Sandy" > wrote in message
...
> On Fri, 26 Sep 2003 17:20:30 +0100, "Paul Landregan"
> > wrote:
>
> >>Check the subnet mask of the machines to ensure they are both on the
same
> >network.
>
>
> Okay, that may be the problem. the subnet mask of computer A is
> 255.255.255.0. The subnet mask of computer B is 255.0.0.0. How to I
> fix this?

Also try this on each computer, go to a command prompt. Start, Run then type
Cmd.

Type Ipconfig /all this will reveal all the IP information you need
including the ip address of the serving DCHP server. if they are different
thn you have a problem, your latched to somebody else's network.

[Sandy]

Xref: kermit alt.internet.wireless:71817 microsoft.public.windowsxp.basics:150161

On Fri, 26 Sep 2003 19:03:04 +0100, "Paul Landregan"
> wrote:

>If this has been DHCP set then your looking at two different
>routers/wireless networks. Are the actual IP's similar eg 192.168.1.1 and
>192.168.1.2 or totally different eg 192.168.1.1 and 10.1.1.1.

Nope, the IPs are the same 192.168.1.1

>If the subnet mask is set manually then right click in network neighbourhood
>to get to network properties, goto TCP/IP properties and enter the correct
>Subnet mask

The IPs are assigned dynamically, so I can't change the subnet mask.

[Sandy]

On Fri, 26 Sep 2003 19:06:03 +0100, "Paul Landregan"
> wrote:

>
>"Sandy" > wrote in message
...
>> On Fri, 26 Sep 2003 17:20:30 +0100, "Paul Landregan"
>> > wrote:
>>
>> >>Check the subnet mask of the machines to ensure they are both on the
>same
>> >network.
>>
>>
>> Okay, that may be the problem. the subnet mask of computer A is
>> 255.255.255.0. The subnet mask of computer B is 255.0.0.0. How to I
>> fix this?
>
>Also try this on each computer, go to a command prompt. Start, Run then type
>Cmd.
>
>Type Ipconfig /all this will reveal all the IP information you need
>including the ip address of the serving DCHP server. if they are different
>thn you have a problem, your latched to somebody else's network.

Okay. I ran winipcfg on the computer I couldn't see and did a RENEW
ALL. This reset the subnet mask to 255.255.255.0. Now if I go back
down to computer A I can see computer B in the DHCP clients table.

I still can't ping computer B and if I try to explore MSHOME on
computer A, it's not accessible. I wonder if part of the problem is
that on computer B, I have four TCP/IP adapters defined:

1) AOL Adapter
2) AOL DIal up adapter
3) PPP adapter
4) Wireless PCI adapter

Not knowing enough, I'm afraid to delete anything without knowing the
consequences, but the subnet mask for the AOL adapter is 255.255.0.0
while the subnet mask for the PCI adapter is 255.255.255.0. COuld
this be causing a conflict?

[Paul Landregan]

"Sandy" > wrote in message
...
> On Fri, 26 Sep 2003 19:03:04 +0100, "Paul Landregan"
> > wrote:
>
> >If this has been DHCP set then your looking at two different
> >routers/wireless networks. Are the actual IP's similar eg 192.168.1.1 and
> >192.168.1.2 or totally different eg 192.168.1.1 and 10.1.1.1.
>
> Nope, the IPs are the same 192.168.1.1
>
> >If the subnet mask is set manually then right click in network
neighbourhood
> >to get to network properties, goto TCP/IP properties and enter the
correct
> >Subnet mask
>
> The IPs are assigned dynamically, so I can't change the subnet mask.
If the 2 IP's of the 2 machines are the same this would explain why they
cant talk to each other.
The IP's must be different but on the same subnet. so 192.168.1.1 and
192.168.1.2 is fine. DCHP should have done this, not give them both the same
address.
>

[Lenny Toulson]

"Sandy" > wrote in message

>
> Okay. I ran winipcfg on the computer I couldn't see and did a RENEW
> ALL. This reset the subnet mask to 255.255.255.0. Now if I go back
> down to computer A I can see computer B in the DHCP clients table.

Subnet mask is only part of the issue. When you ran "renew", did you get a
new IP address along with the new subnet mask?

> I still can't ping computer B and if I try to explore MSHOME on
> computer A, it's not accessible. I wonder if part of the problem is
> that on computer B, I have four TCP/IP adapters defined:

This may be due to still having the same IP address - something that DHCP
should have prevented. Are you *sure* you're not seeing somebody else's
net?

> 1) AOL Adapter
> 2) AOL DIal up adapter
> 3) PPP adapter
> 4) Wireless PCI adapter
>
> Not knowing enough, I'm afraid to delete anything without knowing the
> consequences, but the subnet mask for the AOL adapter is 255.255.0.0
> while the subnet mask for the PCI adapter is 255.255.255.0. COuld
> this be causing a conflict?

I doubt this is an issue. Each of these is bound to a specific adapter and
you should be using only the "Wireless PCI" adapter for your LAN.

Of course, with AOhell... :)

--
Lenny

[Sandy]

On Fri, 26 Sep 2003 19:55:50 GMT, "Lenny Toulson" >
wrote:

>This may be due to still having the same IP address - something that DHCP
>should have prevented. Are you *sure* you're not seeing somebody else's
>net?

Maybe I wasn't clear. The two computers are getting assigned
different IP addresses. 198.162.1.100 and 198.162.1.101

[Sandy]

On Fri, 26 Sep 2003 20:23:45 +0100, "Paul Landregan"
> wrote:

>
>"Sandy" > wrote in message
...
>> On Fri, 26 Sep 2003 19:03:04 +0100, "Paul Landregan"
>> > wrote:
>>
>> >If this has been DHCP set then your looking at two different
>> >routers/wireless networks. Are the actual IP's similar eg 192.168.1.1 and
>> >192.168.1.2 or totally different eg 192.168.1.1 and 10.1.1.1.
>>
>> Nope, the IPs are the same 192.168.1.1

My fault I realized where I created the confusion. When you used the
example of 198.162.1.1 I confused the DHCP server (which is
198.162.1.1) with the IP address. As I replied, the IP addresses are
in deed unique.

[Lenny Toulson]

"Sandy" > wrote in message

>
> Maybe I wasn't clear. The two computers are getting assigned
> different IP addresses. 198.162.1.100 and 198.162.1.101

Well, this is looking much less like a wireless networking issue. :)

I have had problems on one client's "mixed" network running XP and Win98.
However, in that situation all PCs could ping each other, but not browse
shares in Windows Explorer. I finally had to convince them to upgrade to
WinXP to resolve the issue.

Searching groups.google.com will reveal that I wasn't even close to being
alone in having networking issues on XP/98 LANs. I fear you will not be the
last. :) One of the troubleshooting steps recommended for that situation
included removing the NetBEUI protocol from all machines (it's not supported
on XP). Another recommendation was to force its installation on XP (that
didn't help at all in my situation).

I tried a lot of things I found in perusing the archives. Nothing worked -
until they upgraded to XP and everything has worked smoothly ever since.

Is that out of the question for you?

--
Lenny

[Bob Johns]

wk > wrote in :

> From each computer browse to http://checkip.dyndns.org/
>
> Do both of them show the same IP address? If they do then both are
> connected through your router. If not, one of them is connected
> through somebody else's wireless network.
>
> wk
>

Getting into this late but there are no firewalls, right? If there is this
could be the reason the boxes can't see each other.

Bob J.
Guam U.S.A.

[Sandy]

On Fri, 26 Sep 2003 20:46:16 GMT, "Lenny Toulson" >
wrote:

>"Sandy" > wrote in message

>>
>> Maybe I wasn't clear. The two computers are getting assigned
>> different IP addresses. 198.162.1.100 and 198.162.1.101
>
>Well, this is looking much less like a wireless networking issue. :)

I agree since I can use the interenet and see the machine on the DHCP
clients list. After this I'll continue the discussion on
microsoft.public.windowsxp.basics only.


>Searching groups.google.com will reveal that I wasn't even close to being
>alone in having networking issues on XP/98 LANs. I fear you will not be the
>last. :) One of the troubleshooting steps recommended for that situation
>included removing the NetBEUI protocol from all machines (it's not supported
>on XP). Another recommendation was to force its installation on XP (that
>didn't help at all in my situation).

I'll try removing the NetBEUI and see what happens. What I still
can't understand is why it worked at one time and now doesn't. When
that happens, I try to figure out what changed, since it's the most
logical thing to look at.

>I tried a lot of things I found in perusing the archives. Nothing worked -
>until they upgraded to XP and everything has worked smoothly ever since.
>
>Is that out of the question for you?

Yes, as much as I'd like to, it has a 20 gig drive that would have
problems with the change to the boot sector location.

[Sandy]

On Fri, 26 Sep 2003 20:40:39 GMT, Bob Johns >
wrote:


>Getting into this late but there are no firewalls, right? If there is this
>could be the reason the boxes can't see each other.
>
>Bob J.
>Guam U.S.A.

I'm running Norton Internet Security.

New information I just discovered. The laptop can see computer B,
which makes me believe the problem is on the main computer, since it
can't see either computer B or the laptop. As a matter of fact, I
just learned something, I didn't realize that once I disconnected from
VPN, I would be able to "join" the home network. That solves some
minor problems for me, like being able to use my printer.

But I don't want to confuse the issue here. The main question is,
why can the laptop see one computer and not the main computer and why
can't the main computer see the other two. And computer B can see the
laptop. The odd man out seems to be the main computer.

[Paul Shirley]

In message m>, Lenny
Toulson > writes
>I have had problems on one client's "mixed" network running XP and
>Win98. However, in that situation all PCs could ping each other, but
>not browse shares in Windows Explorer. I finally had to convince them
>to upgrade to WinXP to resolve the issue.

Using WinXP's firewall caused similar problems on my mixed network.

--
Paul Shirley: email anti-spammed

[Daniel L. Belton]

There are known issues in accessing Win 98 computers with WinXP over a
network... it takes some playing around with it to get it to work.. It
will work, but takes a few changes..

"Paul Shirley" > wrote in message
...
> In message m>, Lenny
> Toulson > writes
> >I have had problems on one client's "mixed" network running XP and
> >Win98. However, in that situation all PCs could ping each other, but
> >not browse shares in Windows Explorer. I finally had to convince them
> >to upgrade to WinXP to resolve the issue.
>
> Using WinXP's firewall caused similar problems on my mixed network.
>
> --
> Paul Shirley: email anti-spammed

[nuttin]

I'm running win98 and XP and this tutorial explained setting up a mixed
network over the internet, which I decided I didn't want to do..
http://www.homenethelp.com/web/howto/net.asp

"Daniel L. Belton" > wrote in message
...
> There are known issues in accessing Win 98 computers with WinXP over a
> network... it takes some playing around with it to get it to work.. It
> will work, but takes a few changes..
>
> "Paul Shirley" > wrote in message
> ...
> > In message m>, Lenny
> > Toulson > writes
> > >I have had problems on one client's "mixed" network running XP and
> > >Win98. However, in that situation all PCs could ping each other, but
> > >not browse shares in Windows Explorer. I finally had to convince them
> > >to upgrade to WinXP to resolve the issue.
> >
> > Using WinXP's firewall caused similar problems on my mixed network.
> >
> > --
> > Paul Shirley: email anti-spammed
>
>
>

[Sandy]

On Sun, 28 Sep 2003 18:42:18 GMT, "nuttin" > wrote:

>I'm running win98 and XP and this tutorial explained setting up a mixed
>network over the internet, which I decided I didn't want to do..
>http://www.homenethelp.com/web/howto/net.asp
>

Thanks. That tutorial helped a lot. There was a problem with the
workgroup name. In one place it was set to MSHOME, but in another
place it was WORKGROUP. So now I can see the other computer, but
I'm still having problems accessing the drives. I'll have to look
closer. I know I set them up to be shared.

[Sandy]

On Mon, 29 Sep 2003 18:41:15 GMT, Sandy > wrote:

>>Thanks. That tutorial helped a lot. There was a problem with the
>workgroup name. In one place it was set to MSHOME, but in another
>place it was WORKGROUP. So now I can see the other computer, but
>I'm still having problems accessing the drives. I'll have to look
>closer. I know I set them up to be shared.

Still can't access the drives and I know the sharing is set up
correctly, since I can access the drives on computer B from the
laptop. So what other XP oddities to I have to look for?

[CWatters]

Check to see what network connections exist on both machines. I once aquired
an unwanted bridge that seemed to stop everything working.


"Sandy" > wrote in message
...
> A few weeks ago, I set up a home network using a Linksys BEFW11S4
> Router. My desktop(call it A) is directly connected to the router.
> I have a second desktop (call it B) connected via a Wireless PCI card
> and a laptop directly connected. The laptop is for work and has a
> different group name than the other two computers and can't be seen by
> either computer A or computer B, which is expected..
>
> Until recently, I could access computer B from computer A. Now I
> can't. They both belong to group MSHOME. Computer B has no problem
> sharing the internet connection, but if I ping computer A from it, I
> get no response. WEP is enabled and I checked the encryption and it
> looks correct on both ends. Boith are enabled, 64-bit, with the same
> encryption key. If I check the DHCP clients table, computer A shows up
> and so does the laptop, but not computer B. Also, I cannot ping
> computer B from computer A.
>
> I can't think what else to check. I can't think of what I could have
> done to change the network configuration. I'm at wits end. What am I
> missing?

[Sandy]

On Thu, 02 Oct 2003 09:13:30 GMT, "CWatters"
> wrote:

>Check to see what network connections exist on both machines. I once aquired
>an unwanted bridge that seemed to stop everything working.

Meaning? On the XP machine I have two connection defined in my Network
Connections:

Local Area Network - which appears to be the active one.
1394 connection - I honestly cannot figure out what this one is. I
have only one ethernet card that is attached to my cable modem.
Checking my devies - this is identified as the bus controller.

The machine with Windows 98 has four connections defined:

AOL
AOL Dial Up
PPP
Wireless - the one that I'm using. The older ethernet card isn't
attached to anything?

How do I check for an unwanted bridge?

[Douglas Tatelman]

The most common problem "seeing" win98 and xp machines on the same
peer network is due to XP wanting to be the "Browse Master".

If you turn off the browse master on the xp box, things get much
better.

Good Luck

Douglas Tatelman
www.pickteam.com

[Sandy]

On 2 Oct 2003 16:00:59 -0700, (Douglas Tatelman)
wrote:

>The most common problem "seeing" win98 and xp machines on the same
>peer network is due to XP wanting to be the "Browse Master".
>
>If you turn off the browse master on the xp box, things get much
>better.
>
>Good Luck
>
>Douglas Tatelman
>www.pickteam.com

Can you clue me in to what a Browse Master is and how I control it?
Search for "browse master" turned up zero results and search for
"browse" is too general.

[Sharkman@comcast.net]

If you are using a firewall, check to see that the PC's are passing thru.
Turn them off to test. In zone alarm, you need to add the IP addresses to
the "trusted zone" setting.

"Sandy" > wrote in message
...
> On 2 Oct 2003 16:00:59 -0700, (Douglas Tatelman)
> wrote:
>
> >The most common problem "seeing" win98 and xp machines on the same
> >peer network is due to XP wanting to be the "Browse Master".
> >
> >If you turn off the browse master on the xp box, things get much
> >better.
> >
> >Good Luck
> >
> >Douglas Tatelman
> >www.pickteam.com
>
> Can you clue me in to what a Browse Master is and how I control it?
> Search for "browse master" turned up zero results and search for
> "browse" is too general.

[Sandy]

On Fri, 3 Oct 2003 07:10:35 -0400, "
> wrote:

>If you are using a firewall, check to see that the PC's are passing thru.
>Turn them off to test. In zone alarm, you need to add the IP addresses to
>the "trusted zone" setting.

The PCs must be passing through is they can see the interenet. And I
use Norton Internet Security, which picks up the IP address of the
router 192.168.1.0 subnet mask 255.255.255.0 and plces it in the
trusted zone.