"This computer cannot connect to the remote computer..."

[Tim J.]

I have a friend who has 5 computers networked. There are four Dells
with XP Home, and one eMachine (yeah, yeah, I know) running Vista
Home. All Windows updates are current. This has been his hardware
and OS configuration for the past 2+ years.

But a couple of weeks ago, they encountered a strange problem. One of
their Dells won't connect to their Dell (XP Home) server anymore. It
gives the message "This computer cannot connect to the remote
computer..." and makes reference to the computer we're trying to
connect to has reached the maximum number of inbound network
connections. The server is running QuickBooks and MS Office and
allowing access to the other computers, also running QB and MSO, via
mapped drives letters to shared folders on the server. Again, this
setup seemed to work just fine for more than 2 years.

I have since discovered that XP Home has a limit of 5 concurrent
inbound connections, but no more than 4 computers are trying to access
the server at any . So I'm trying to figure out where those other
connection(s) are coming from. Last year, I turned off wireless
networking for security reasons, and everything seem to run fine after
that.

I visited him today to try to figure out the problem, and only found
that if I reboot one connected machine, it allows the "odd man out"
machine to connect, but the rebooted computer will no longer connect
unless I reboot another machine. It's almost as if we're trying to
establish 6 connections, but I'm stumped as to where the extra
connections are coming from.

But first, a bit of background.

1. We are not utilizing Remote Desktop Connection, VPN, or any other
remote access to the network.

2. Wireless networking has been turned off through the router setup.

3. Terminal Services/Remote Desktop Service isn't being used.

4. Remote Assistance is not being used.

5. All five computers share internet access (DSL).

6. Each computer has only one NIC installed.

7. No other hardware or software changes (except for critical Windows
updates) have been made.

The obvious fix to me is to upgrade the server to Windows 7, but I
don't think that computer can handle it.

Can anyone point me to a webpage which explains how network
connections are established and maintained, or suggest ideas for
tracking down and resolving this problem?

Thanks in advance!

 

[MyNews]

Do you thank it's time to get a Network Router with a good Firewall!

 

[Nil]

I have since discovered that XP Home has a limit of 5 concurrent
inbound connections, but no more than 4 computers are trying to
access the server at any . So I'm trying to figure out where
those other connection(s) are coming from.

The limit is CONNECTIONS, not machines. Any one machine can make many
connections to the server. A single computer could use all the
allowable connections if it is accessing several resources on the
server.

 

[Paul]

The limit is CONNECTIONS, not machines. Any one machine can make many
connections to the server. A single computer could use all the
allowable connections if it is accessing several resources on the
server.

"Inbound connections limit in Windows XP"
http://support.microsoft.com/kb/314882

"For Windows XP Professional, the maximum number of other computers
that are permitted to simultaneously connect over the network is ten.
This limit includes all transports and resource sharing protocols
combined.

For Windows XP Home Edition, the maximum number of other computers
that are permitted to simultaneously connect over the network is five.
This limit is the number of simultaneous sessions from other computers
the system is permitted to host. This limit does not apply to the use
of administrative tools that attach from a remote computer."

You might try this program. It shows connections. But perhaps,
not in a way that immediately points out you've hit the limit.
You can run this on both ends, on the client machine and the
server machine. And see what resources are being used. Maybe
you'll see a connection for printing, and another connection for
a file share ? I don't have printing set up here, so I can't
check.

TCPView
http://technet.microsoft.com/en-us/sysinternals/bb897437

I tested using a Win98 virtual machine (which has a shared C: drive
set up), and using netstat in Win98, I can see one active connection,
while I'm accessing the share from the WinXP side. So between
tcpview and netstat, you should be able to observe and figure it out.

Paul

 

[Tim J.]

"Inbound connections limit in Windows XP"
http://support.microsoft.com/kb/314882

"For Windows XP Professional, the maximum number of other computers
that are permitted to simultaneously connect over the network is ten.
This limit includes all transports and resource sharing protocols
combined.

For Windows XP Home Edition, the maximum number of other computers
that are permitted to simultaneously connect over the network is five.
This limit is the number of simultaneous sessions from other computers
the system is permitted to host. This limit does not apply to the use
of administrative tools that attach from a remote computer."

You might try this program. It shows connections. But perhaps,
not in a way that immediately points out you've hit the limit.
You can run this on both ends, on the client machine and the
server machine. And see what resources are being used. Maybe
you'll see a connection for printing, and another connection for
a file share ? I don't have printing set up here, so I can't
check.

TCPView
http://technet.microsoft.com/en-us/sysinternals/bb897437

I tested using a Win98 virtual machine (which has a shared C: drive
set up), and using netstat in Win98, I can see one active connection,
while I'm accessing the share from the WinXP side. So between
tcpview and netstat, you should be able to observe and figure it out.

After reviewing their entire network setup, I discovered the
following:

SERVER had a shared folder mapped as both drive E and drive F on
COMPUTER-1 and COMPUTER-2. Also, COMPUTER-1 and COMPUTER-2 each had a
virtual mapping to a COMPUTER-5, which no longer exists.

COMPUTER-3 and COMPUTER-4 were fine.

Once I deleted the mappings to the non-existent computer and rebooted
all the computers, the duplicated mappings to the server disappeared
and the error message went away.

Thanks to all who replied.

 

[Nil]

After reviewing their entire network setup, I discovered the
following:

SERVER had a shared folder mapped as both drive E and drive F on
COMPUTER-1 and COMPUTER-2. Also, COMPUTER-1 and COMPUTER-2 each
had a virtual mapping to a COMPUTER-5, which no longer exists.

COMPUTER-3 and COMPUTER-4 were fine.

Once I deleted the mappings to the non-existent computer and
rebooted all the computers, the duplicated mappings to the server
disappeared and the error message went away.

Thanks to all who replied.

Thank you for the follow-up. It's good to have the resolution in the
archive, in case someone later is searching for answers to a similar
problem.

 

[Tim J.]

Thank you for the follow-up. It's good to have the resolution in the
archive, in case someone later is searching for answers to a similar
problem.

You're welcome. I still can't figure out how the mappings to the
non-existent computer had persisted for so long. That computer (#5)
had been disconnected over 2 years ago. When I don't have one of my
networked machines on, its mappings are either marked as unavailable
or just don't show up at all. And I found it strange that the
duplicated virtual drive mappings on the server couldn't be
disconnected until the mappings to the non-existent computer on #'s 1
and 2 were removed. The all computers are all XP Home (except for
Vista Home Prem. on #4), and all have been repeatedly scanned using
NIS.

Windows can be a fickle beast sometimes.