WINXP Pro computers disappear from Network Places

I have a network of five computers, all windows xp pro, no servers or
domains, and all in same workgroup. Static IP (manually configured, not
DHCP). When I restart my pc I can see all of them in Network Places, then
after about 20 minutes, 3 of them (including mine) disappear. I can ping
them, and still access mapped drives but can not see them in network places.

I have checked ipconfig, ran cdiag, and browstat. XP firewall is disabled, I
have KIS 7.0 and tried with and without it disabled with same results. The
network has run fine for about 2 years, then about 2 weeks ago the PC's start
disappearing.

I have checked the browser service, even stopped them and restarted, checked
power management, file and print sharing enabled, and for IP address
conflicts.

All computers have unique ip's, same subnet, dns, workgroup name, and
default gateway.

If you need more info let me know. Thanks in advance for any help.

=?Utf-8?B?ZnIzYWtkMQ==?= <fr3akd1@discussions.microsoft.com> wrote
in news:4FD05A33-D9DF-4046-B242-AE2E558C4172@microsoft.com:

> I have a network of five computers, all windows xp pro, no servers
> or domains, and all in same workgroup. Static IP (manually
> configured, not DHCP). When I restart my pc I can see all of them
> in Network Places, then after about 20 minutes, 3 of them
> (including mine) disappear. I can ping them, and still access
> mapped drives but can not see them in network places.
>
> I have checked ipconfig, ran cdiag, and browstat. XP firewall is
> disabled, I have KIS 7.0 and tried with and without it disabled
> with same results. The network has run fine for about 2 years,
> then about 2 weeks ago the PC's start disappearing.
>
> I have checked the browser service, even stopped them and
> restarted, checked power management, file and print sharing
> enabled, and for IP address conflicts.
>
> All computers have unique ip's, same subnet, dns, workgroup name,
> and default gateway.
>
> If you need more info let me know. Thanks in advance for any help.
>

This has the look/feel of a computer browser problem usually caused
by just one machine on the network with a firewall. Even though the
browser service is running on every computer, only the one computer
serving as Browse Master really needs to have it running. This
Browse master maintains the list of computers on the network and
gives it to any machine that requests it when opening Network Places.

What happens when one computer has a firewall is that the firewall
blocks the NetBT broadcasts and it thinks that it is the only machine
on the network so it elects itself as Browse master. The firewall
effectively prevents it from finding out about other computers and
adding them to the list, so its list is empty except for itself. The
reason that it works for a few minutes after you power up is because
the computer that was really elected as the Browse master starts up
and works for a while until the firewalled computer convinces the
real Browse Master that it really is not the browse master, causing
it to shut down.

The way I've been able to verify this is to use browstat to force a
browser election:
browstat elect <interface> <workgroup>
then, over the next minute or so, use browstat to view the network:
browstat view <interface> <workgroup>
Examine the view output and if you see more than one computer with
the Master Browser (MBR) status, then this is your problem. One of
these machines is your problem machine.

With only 5 machines, you could try getting a network to work
properly with only two computers and add computers one-by-one until
the problem resurfaces.

Another debug method would be to disable the browser service on all
but one computer (then add in additional ones in one-by-one until you
find the problem computer).

Keep in mind that when looking for firewalls, VPN Clients (such as
the Cisco VPN Client) often have a firewall built-in as well.

"Troubleshooting the Microsoft Computer Browser Service"
<http://support.microsoft.com/kb/188305>

HTH,
John

I checked on the browser issue. Disabled all browser services except on one
machine, shut everything down and turned Master Browser on first. This
worked fine for about an hour, then 1 by 1 the same three pc's disappeared.
Even the one that is set as the Master Browser. Disabled all firewalls and
suspected firewall software.

"John Wunderlich" wrote:

> =?Utf-8?B?ZnIzYWtkMQ==?= <fr3akd1@discussions.microsoft.com> wrote
> in news:4FD05A33-D9DF-4046-B242-AE2E558C4172@microsoft.com:
>
> > I have a network of five computers, all windows xp pro, no servers
> > or domains, and all in same workgroup. Static IP (manually
> > configured, not DHCP). When I restart my pc I can see all of them
> > in Network Places, then after about 20 minutes, 3 of them
> > (including mine) disappear. I can ping them, and still access
> > mapped drives but can not see them in network places.
> >
> > I have checked ipconfig, ran cdiag, and browstat. XP firewall is
> > disabled, I have KIS 7.0 and tried with and without it disabled
> > with same results. The network has run fine for about 2 years,
> > then about 2 weeks ago the PC's start disappearing.
> >
> > I have checked the browser service, even stopped them and
> > restarted, checked power management, file and print sharing
> > enabled, and for IP address conflicts.
> >
> > All computers have unique ip's, same subnet, dns, workgroup name,
> > and default gateway.
> >
> > If you need more info let me know. Thanks in advance for any help.
> >
>
> This has the look/feel of a computer browser problem usually caused
> by just one machine on the network with a firewall. Even though the
> browser service is running on every computer, only the one computer
> serving as Browse Master really needs to have it running. This
> Browse master maintains the list of computers on the network and
> gives it to any machine that requests it when opening Network Places.
>
> What happens when one computer has a firewall is that the firewall
> blocks the NetBT broadcasts and it thinks that it is the only machine
> on the network so it elects itself as Browse master. The firewall
> effectively prevents it from finding out about other computers and
> adding them to the list, so its list is empty except for itself. The
> reason that it works for a few minutes after you power up is because
> the computer that was really elected as the Browse master starts up
> and works for a while until the firewalled computer convinces the
> real Browse Master that it really is not the browse master, causing
> it to shut down.
>
> The way I've been able to verify this is to use browstat to force a
> browser election:
> browstat elect <interface> <workgroup>
> then, over the next minute or so, use browstat to view the network:
> browstat view <interface> <workgroup>
> Examine the view output and if you see more than one computer with
> the Master Browser (MBR) status, then this is your problem. One of
> these machines is your problem machine.
>
> With only 5 machines, you could try getting a network to work
> properly with only two computers and add computers one-by-one until
> the problem resurfaces.
>
> Another debug method would be to disable the browser service on all
> but one computer (then add in additional ones in one-by-one until you
> find the problem computer).
>
> Keep in mind that when looking for firewalls, VPN Clients (such as
> the Cisco VPN Client) often have a firewall built-in as well.
>
> "Troubleshooting the Microsoft Computer Browser Service"
> <http://support.microsoft.com/kb/188305>
>
> HTH,
> John
>
>

=?Utf-8?B?ZnIzYWtkMQ==?= <fr3akd1@discussions.microsoft.com> wrote
in news:8CCB80E4-2AE8-4399-8F9B-100C498D377E@microsoft.com:

> I checked on the browser issue. Disabled all browser services
> except on one machine, shut everything down and turned Master
> Browser on first. This worked fine for about an hour, then 1 by 1
> the same three pc's disappeared. Even the one that is set as the
> Master Browser. Disabled all firewalls and suspected firewall
> software.
>

Strange. You might try a:
browstat forceannounce <interface> <workgroup>
command. This should cause all the computers on the network to
announce themselves to the browse master and cause them to re-appear in
the list.

You might also try using a different computer as the browse master.

Good Luck.
John