Problem Pinging

[local]

One of the smaller networks that I maintain has a strange problem. There
are about 10 client PCs running Win2k or WinXP, and 2 Servers running Win2k
Server. All of the PCs can access the first server. Some can access the
second server, some can't.

I tried pinging the server from one of the client PCs and it times out. The
same is true in the opposite direction.
All of the computers are in the same subnet, connected to a single unmanaged
hub. The computers that can connect to both servers can ping every other
computer on the network. I tried swapping IP addresses between a computer I
could ping, and one I couldn't - no good. I even changed the ports on the
hub.

Any ideas?

 

[Pegasus \(MVP\)]

One of the smaller networks that I maintain has a strange problem. There
are about 10 client PCs running Win2k or WinXP, and 2 Servers running Win2k
Server. All of the PCs can access the first server. Some can access the
second server, some can't.

I tried pinging the server from one of the client PCs and it times out. The
same is true in the opposite direction.
All of the computers are in the same subnet, connected to a single unmanaged
hub. The computers that can connect to both servers can ping every other
computer on the network. I tried swapping IP addresses between a computer I
could ping, and one I couldn't - no good. I even changed the ports on the
hub.

Any ideas?

Turn off your WinXP firewall while testing.

 

[Steven L Umbach]

Try booting the W2K server into safemode with networking to see if it makes
a difference. If it does I would suspect an ipsec policy configured on the
server. --- Steve

 

[John Cranston]

Actually the test machine in Windows 2000. The WinXP PCs seem to be
working.

 

[Pegasus \(MVP\)]

Some Win2000 PCs have firewalls too, e.g. ZoneAlarm,
Trend Internet Security, Norton Internet Security etc. etc.

 

[John Cranston]

I'll check for a firewall.

The thing that doesn't make sense is other computers can ping the same
machine.

PC1 can ping PC2
PC2 can ping PC1

PC1 can ping Server1
Server1 can ping PC1

PC2 cannot ping Server1
Server2 cannot ping PC1

Since PC1 and 2 can ping each other, and I am sure all of the IP addresses
are in the same subnet, the loss of conectivity betwen PC2 and the server is
frustrating.

Thanks for answering though.

 

[Pegasus \(MVP\)]

How many machines do you have?
- PC1, PC2
- Server1, Server2?

Have you performed ALL ping tests?
- PC1 to PC2, Server1 & Server2
- PC2 to PC1, Server1 & Server2
- Server1 to PC1, PC2 & Server2
- Server2 to PC1, PC2 & Server1
That's 12 tests, yet you listed only 6 of them!

What do you mean with "I am sure all of the IP addresses
are in the same subnet"? This is not a matter of faith: Either
they are in the same subnet, or they are not!

 

[John Cranston]

I physically checked the IP address, subnet mask, gateway and DNS settings
on every computer on the network. That is 2 servers, 9 PCs, and 2 Macs.
All of the subnet masks and gateways are the same. There were a couple of
variations on DNS servers, but all are valid and the primary DNS on all
machines is the same. The IP address have the same 3 leading octets, and
the final octet is sequentil.

 

[Pegasus \(MVP\)]

If there is a random pattern of some PCs being pingable and
others not then you may have a cabling issue. Drop your speed
to 10 MBits/s half duplex during the tests. You should also
have a closer look at your hub/switch.

Lastly, have a look at your PC clock or time zone. You are
about half an hour ahead of the rest of the world!

 

[John Cranston]

I did not test pinging from every computer to every computer. I
concentrated on 3 PCs (with the 2 servers) and listed results for 2 PCs as
it is representative of the problem. There are no software firewalls
installed on the PCs or servers. The only firewall is a hardware filewall
and every computer passes through this to the internet without issue. I
have swapped cables, replaced cables, swapped ports on the hub and later I
will try direct connections via a cross-over cable, but I am unable to do
this while people are working.

There is no issue with the Macs at this time, as they only share the cabling
for internet access and both Macs are able to ping both servers (even though
they donlt need to access them). Every PC can be pinged from the first
server, and about half are ping-able from the second. There is one computer
that I tested that was able to ping all of the IP addresses. I am unsure of
the results of every single combination of computer pinging the others.