Sharing fine, but ping fails...?

[Kenneth]

Howdy,

We have a five node net. All systems are Win 2K Pro, and all run
TCP/IP as their only network protocol.

Let's call two of the systems "A" and "B".

These two can read and write files to one another from within windows.

That would seem to indicate that the network functions were in good
shape, but when I attempt to ping system "A" from system "B", it fails
every time.

What might cause ping to fail (specifically to time out) if files can
be moved back and forth over the net properly?

(I am asking because I had Public Outlook working properly between
these two systems, and now can't get it running again. I get an error
telling me that the Public Outlook server cannot be reached. It was
their manual that suggested testing with ping...)

Thanks for any information on this,

 

[Kenneth]

Howdy,

We have a five node net. All systems are Win 2K Pro, and all run
TCP/IP as their only network protocol.

Let's call two of the systems "A" and "B".

These two can read and write files to one another from within windows.

That would seem to indicate that the network functions were in good
shape, but when I attempt to ping system "A" from system "B", it fails
every time.

What might cause ping to fail (specifically to time out) if files can
be moved back and forth over the net properly?

(I am asking because I had Public Outlook working properly between
these two systems, and now can't get it running again. I get an error
telling me that the Public Outlook server cannot be reached. It was
their manual that suggested testing with ping...)

Thanks for any information on this,

I should add that this is a peer to peer, and runs through a switch...

 

[Imran Sadat]

You should see if the ICMP Port 7 is enabled and echo of packets is allowed.
There shouldn't be any firewalls blocking it.

Imran.

 

[Kenneth]

You should see if the ICMP Port 7 is enabled and echo of packets is allowed.
There shouldn't be any firewalls blocking it.

Imran.




Hi Imran,

I thank you for your response, but do not know how to do the things
you suggest.

Can you describe what I should do on a Win 2000 Pro box to "see if the
ICMP Port 7 is enabled and echo of packets is allowed."

I have checked that there is no firewall blocking problem...

Sincere thanks,

Hello again,

I just tried pinging by "name" rather than IP address and got a bit of
a surprise.

If I enter "ping joe" it fails, and displays an IP address that is NOT
correct for Joe's system.

Why might that occur, that is, why might the system name not be
associated with the correct system IP address?

Thanks again,

 

[Imran Sadat]

Hi Kenneth,

To check if the firewall is enabled go to network connection and see the
properties for the adapter. In the advanced tab see if there is a tick mark
in front of the firewall. If you want to use the firewall you can click on
the settings under the same tab and go to ICMP. There you will have to check
on allow incoming echo requests for the ping to work.

Do you have a DNS Server or a WINS Server installed in your network? What
are the settings on your machines for these two addresses?

 

[Imran Sadat]

Hi Kenneth,

To check if the firewall is enabled go to network connection and see the
properties for the adapter. In the advanced tab see if there is a tick mark
in front of the firewall. If you want to use the firewall you can click on
the settings under the same tab and go to ICMP. There you will have to check
on allow incoming echo requests for the ping to work.

Do you have a DNS Server or a WINS Server installed in your network? What
are the settings on your machines for these two addresses?

 

[Kenneth]

Hi Kenneth,

To check if the firewall is enabled go to network connection and see the
properties for the adapter. In the advanced tab see if there is a tick mark
in front of the firewall. If you want to use the firewall you can click on
the settings under the same tab and go to ICMP. There you will have to check
on allow incoming echo requests for the ping to work.

Do you have a DNS Server or a WINS Server installed in your network? What
are the settings on your machines for these two addresses?

Hello again,

I just tried pinging by "name" rather than IP address and got a bit of
a surprise.

If I enter "ping joe" it fails, and displays an IP address that is NOT
correct for Joe's system.

Why might that occur, that is, why might the system name not be
associated with the correct system IP address?

Thanks again,

Hi Imran,

You said "To check if the firewall is enabled go to network connection
and see the properties for the adapter."

In network properties, I see the Lan and in its properties I see
"Client for Microsoft networks", "File and Printer sharing", and
TCP/IP. In none of those is there any mention of firewall issues (that
I can find.) I also checked the properties of the NIC in Device
Manager. Is there some other place that I should be looking?

I do run ZoneAlarm, and on each machine I have all the IP addresses of
our small net entered as "Trusted."

I do not have a WINS or a DNS server on the network. On each system,
In TCP/IP properties, I have "Obtain DNS serve address automatically"
checked. On the WINS tab, there are no entries at the top. Below,
"Enable LM Hosts lookup" is checked. "Use NETBIOS setting from the
DHCP server" is also checked.

Thanks for any further help,

 

[Madhur Ahuja]

Hello again,

I just tried pinging by "name" rather than IP address and got a bit of
a surprise.

If I enter "ping joe" it fails, and displays an IP address that is NOT
correct for Joe's system.

Why might that occur, that is, why might the system name not be
associated with the correct system IP address?

This normally occurs when a wrong entry has been made in the hosts file.
Open the *%systemroot%\system32\drivers\etc\hosts* file in notepad and
delete all lines except this:


127.0.0.1 localhost

HTH

 

[Madhur Ahuja]

Hi Kenneth,

To check if the firewall is enabled go to network connection and see
the properties for the adapter. In the advanced tab see if there is
a tick mark in front of the firewall. If you want to use the
firewall you can click on the settings under the same tab and go to
ICMP. There you will have to check on allow incoming echo requests
for the ping to work.

Do you have a DNS Server or a WINS Server installed in your network?
What are the settings on your machines for these two addresses?




Hi Imran,

You said "To check if the firewall is enabled go to network connection
and see the properties for the adapter."

In network properties, I see the Lan and in its properties I see
"Client for Microsoft networks", "File and Printer sharing", and
TCP/IP. In none of those is there any mention of firewall issues (that
I can find.) I also checked the properties of the NIC in Device
Manager. Is there some other place that I should be looking?

The firewall thing which Imran referred is only available on Windows XP.
In Windows 2000, partial functionality of firewall is available through
TCP/IP filtering, which I dont think is the problem in your case.

I do run ZoneAlarm, and on each machine I have all the IP addresses of
our small net entered as "Trusted."

Try disabling ZoneAlarm, and then ping the other computer. If this doesnt
solve your problem, you might want to get a packet sniffer like
www.ethereal.com and see whether the *echo reply* packets are really being
dropped by some firewall.

 

[Kenneth]

This normally occurs when a wrong entry has been made in the hosts file.
Open the *%systemroot%\system32\drivers\etc\hosts* file in notepad and
delete all lines except this:


127.0.0.1 localhost

HTH

Hi Madhur,

Very sincere thanks...!

As it turns out, I was giving the systems "mixed messages." A while
ago, in an attempt to correct another problem, I tried listing all the
systems in the Hosts file.

Later, with dynamically assigned IP addresses, those entries became
obsolete. I have removed them as per your suggestion, and will test
further.

Thanks again,

 

[Kenneth]

This normally occurs when a wrong entry has been made in the hosts file.
Open the *%systemroot%\system32\drivers\etc\hosts* file in notepad and
delete all lines except this:


127.0.0.1 localhost

HTH

Hi Again Madhur,

Your suggestion has solved the problem that I was having!!

Sincere thanks,

 

[Kenneth]

This normally occurs when a wrong entry has been made in the hosts file.
Open the *%systemroot%\system32\drivers\etc\hosts* file in notepad and
delete all lines except this:


127.0.0.1 localhost

HTH

Hello again Madhur,

I am now having another problem that I assume is related:

My network mappings no longer seem to work.

If I remove a mapping, and then try to rebuild it, here is what
happens:

If I enter the remote system as \\server\filename I get the error that
it is not available.

If I attempt to browse to it, I click "Entire Network" and the system
displays "Microsoft Windows Network." Then if I expand, it correctly
displays our Workgroup ("Office"). But then, if I click the "+" or
right click to Open, or Explore, I get the error "Office is not
accessible. The list of servers for this workgroup is not currently
available."

I then tried to reboot, but that did not help...

Might you suggest a next step to sort this out?

Very sincere thanks,

 

[Kenneth]

Hello again Madhur,

I am now having another problem that I assume is related:

My network mappings no longer seem to work.

If I remove a mapping, and then try to rebuild it, here is what
happens:

If I enter the remote system as \\server\filename I get the error that
it is not available.

If I attempt to browse to it, I click "Entire Network" and the system
displays "Microsoft Windows Network." Then if I expand, it correctly
displays our Workgroup ("Office"). But then, if I click the "+" or
right click to Open, or Explore, I get the error "Office is not
accessible. The list of servers for this workgroup is not currently
available."

I then tried to reboot, but that did not help...

Might you suggest a next step to sort this out?

Very sincere thanks,

Hello yet again Madhur,

I researched my problem on the MSKB, and came up with what I thought
would help. I found that though I am using dynamic IP address
assignments, some of the systems did not have "Use NetBIOS setting
from the DHCP server" checked. I checked that setting, and re-booted
each machine.

As it turned out, that did not "fix" my problem, but it did change it.

Now, when I click on "Entire Network" and drop it down, it displays,
Microsoft Windows Network, and then "Office" (our workgroup.)

But, when I double click on Office, I get the error: "Office is not
accessible. The network path was not found."

I should add that I can ping each way successfully using IP addresses,
or names between several of the five systems, but not all. Two ping
successfully by IP Address, but fail by name...

Might you have any suggestions on this?

Very sincere thanks,

 

[Madhur Ahuja]

[snip]
Hello again,

I just tried pinging by "name" rather than IP address and got a
bit of a surprise.

If I enter "ping joe" it fails, and displays an IP address that is
NOT correct for Joe's system.

Why might that occur, that is, why might the system name not be
associated with the correct system IP address?

This normally occurs when a wrong entry has been made in the hosts
file. Open the *%systemroot%\system32\drivers\etc\hosts* file in
notepad and delete all lines except this:


127.0.0.1 localhost

HTH

Hello again Madhur,

I am now having another problem that I assume is related:

My network mappings no longer seem to work.

If I remove a mapping, and then try to rebuild it, here is what
happens:

If I enter the remote system as \\server\filename I get the error
that it is not available.

If I attempt to browse to it, I click "Entire Network" and the system
displays "Microsoft Windows Network." Then if I expand, it correctly
displays our Workgroup ("Office"). But then, if I click the "+" or
right click to Open, or Explore, I get the error "Office is not
accessible. The list of servers for this workgroup is not currently
available."

I then tried to reboot, but that did not help...

Might you suggest a next step to sort this out?

Very sincere thanks,

Hello yet again Madhur,

I researched my problem on the MSKB, and came up with what I thought
would help. I found that though I am using dynamic IP address
assignments, some of the systems did not have "Use NetBIOS setting
from the DHCP server" checked. I checked that setting, and re-booted
each machine.

As it turned out, that did not "fix" my problem, but it did change it.

Now, when I click on "Entire Network" and drop it down, it displays,
Microsoft Windows Network, and then "Office" (our workgroup.)

But, when I double click on Office, I get the error: "Office is not
accessible. The network path was not found."

This problem can be due to disabled File and Printer Sharing. See in your
network properties that it is *Installed and Checked*.

Also make sure that common username and passwords acounts exist in the
machines.

The output of *nbtstat -a <computername>* should include 20 in the TYPE
field as in:

Name Type Status
---------------------------------------------
MADHUR <00> UNIQUE Registered
MADHUR <20> UNIQUE Registered
OSWAL <00> GROUP Registered
OSWAL <1E> GROUP Registered
OSWAL <1D> UNIQUE Registered
..__MSBROWSE__.<01> GROUP Registered

MAC Address = 00-08-A1-5F-A7-D6

Also, what do you get when you do *net view \\compname*

I should add that I can ping each way successfully using IP addresses,
or names between several of the five systems, but not all. Two ping
successfully by IP Address, but fail by name...

Since you are not using WINS server on your network, this is probably an
either firewall issue or a *Master Browser contention issue*.

* Make sure that NetBIOS is enabled in each PC and any firewall is disabled.
* All are in same subnet since, hubs do not broadcast between hubs.
* All are in same workgroup

 

[Kenneth]

Hello Madhur,

Please see my comments inline below... (and accept my apology for all
the detail...)

[snip]
Hello again,

I just tried pinging by "name" rather than IP address and got a
bit of a surprise.

If I enter "ping joe" it fails, and displays an IP address that is
NOT correct for Joe's system.

Why might that occur, that is, why might the system name not be
associated with the correct system IP address?

This normally occurs when a wrong entry has been made in the hosts
file. Open the *%systemroot%\system32\drivers\etc\hosts* file in
notepad and delete all lines except this:


127.0.0.1 localhost

HTH

Hello again Madhur,

I am now having another problem that I assume is related:

My network mappings no longer seem to work.

If I remove a mapping, and then try to rebuild it, here is what
happens:

If I enter the remote system as \\server\filename I get the error
that it is not available.

If I attempt to browse to it, I click "Entire Network" and the system
displays "Microsoft Windows Network." Then if I expand, it correctly
displays our Workgroup ("Office"). But then, if I click the "+" or
right click to Open, or Explore, I get the error "Office is not
accessible. The list of servers for this workgroup is not currently
available."

I then tried to reboot, but that did not help...

Might you suggest a next step to sort this out?

Very sincere thanks,

Hello yet again Madhur,

I researched my problem on the MSKB, and came up with what I thought
would help. I found that though I am using dynamic IP address
assignments, some of the systems did not have "Use NetBIOS setting
from the DHCP server" checked. I checked that setting, and re-booted
each machine.

As it turned out, that did not "fix" my problem, but it did change it.

Now, when I click on "Entire Network" and drop it down, it displays,
Microsoft Windows Network, and then "Office" (our workgroup.)

But, when I double click on Office, I get the error: "Office is not
accessible. The network path was not found."

This problem can be due to disabled File and Printer Sharing. See in your
network properties that it is *Installed and Checked*.

On system "A" I did have File and Printer sharing installed and
checked. Because I thought it might be corrupted, I removed it,
rebooted, and then reinstalled it.

Now, I am still unable to open files on system "A" from system "B". I
can open files on "A" from system "C" or "D" however.

Also make sure that common username and passwords acounts exist in the
machines.

Everything with regard to Users and Passwords looks fine...

The output of *nbtstat -a <computername>* should include 20 in the TYPE
field as in:

Name Type Status
---------------------------------------------
MADHUR <00> UNIQUE Registered
MADHUR <20> UNIQUE Registered
OSWAL <00> GROUP Registered
OSWAL <1E> GROUP Registered
OSWAL <1D> UNIQUE Registered
..__MSBROWSE__.<01> GROUP Registered

MAC Address = 00-08-A1-5F-A7-D6

When I run NBTSTAT -a "A" I get the proper result as you display
above.

Also, what do you get when you do *net view \\compname*

When I run Net View, I get "System Error 53 The network path was not
found"




I shut down the firewall on system "A".

Right now, when I ping system "A" from system "B" by name or by IP
address it succeeds.

I then went to system "A" and tried to ping system "B". When trying by
IP address, it times out. When trying using the name of system "B" it
give "Unknown Host" error.

But then it got more weird.

I went back to system "B" and tried to ping "A" again. Now, ping
succeeds when I enter the IP address of "A", but when I enter the name
of "A" I get "Unknown Host." Absolutely nothing had changed on either
system between these two efforts.

About three minutes later, I tried again. Now, when I ping system "A"
from system "B" by name, or by IP address, it succeeds once again.

Because both versions of pinging "A" succeeded, I tried again to
"open" system "A" by browsing from system "B". I got the now familiar
error "A" is not accessible. The network path was not found.

I then went to system "C" and using exactly the same technique
attempted to browse files on system "A". They opened immediately.

Then, from system "C" I tried to browse system "B" but, to my
surprise, I could not. I got the error "The network path was not
found." Based on my earlier experience, I uninstalled, then
reinstalled File & Printer Sharing. With that, I could browse files on
"B" from "C". Of course, I immediately tried to browse "A" from "B",
but it still does not work. I got the "The network path was not found"
error.

When I try to browse files on "B" from "A" I get the same error.

Since you are not using WINS server on your network, this is probably an
either firewall issue or a *Master Browser contention issue*.

* Make sure that NetBIOS is enabled in each PC and any firewall is disabled.
* All are in same subnet since, hubs do not broadcast between hubs.
* All are in same workgroup

I assume that enabling NetBios means having File and Printer Sharing
enabled. Is that correct?

All systems are on the same subnet (255.255.255.0)

All systems are in the same workgroup (OFFICE).

As before, I am most appreciative of your help,

 

[Madhur Ahuja]

On system "A" I did have File and Printer sharing installed and
checked. Because I thought it might be corrupted, I removed it,
rebooted, and then reinstalled it.

Now, I am still unable to open files on system "A" from system "B". I
can open files on "A" from system "C" or "D" however.

This indicates that problem could be in B rather than A.

Also make sure that common username and passwords acounts exist in
the machines.

Everything with regard to Users and Passwords looks fine...
[...]

I shut down the firewall on system "A".

Right now, when I ping system "A" from system "B" by name or by IP
address it succeeds.

I then went to system "A" and tried to ping system "B". When trying by
IP address, it times out. When trying using the name of system "B" it
give "Unknown Host" error.

But then it got more weird.

I went back to system "B" and tried to ping "A" again. Now, ping
succeeds when I enter the IP address of "A", but when I enter the name
of "A" I get "Unknown Host." Absolutely nothing had changed on either
system between these two efforts.

About three minutes later, I tried again. Now, when I ping system "A"
from system "B" by name, or by IP address, it succeeds once again.

Because both versions of pinging "A" succeeded, I tried again to
"open" system "A" by browsing from system "B". I got the now familiar
error "A" is not accessible. The network path was not found.

I then went to system "C" and using exactly the same technique
attempted to browse files on system "A". They opened immediately.

Then, from system "C" I tried to browse system "B" but, to my
surprise, I could not. I got the error "The network path was not
found." Based on my earlier experience, I uninstalled, then
reinstalled File & Printer Sharing. With that, I could browse files on
"B" from "C". Of course, I immediately tried to browse "A" from "B",
but it still does not work. I got the "The network path was not found"
error.

When I try to browse files on "B" from "A" I get the same error.

Very Strange results.

I would suggest you to perform a virus scan and scan for spywares and
adawares.

spyware removal spybot -- http://www.safer-networking.org
Another spyware remove ad-aware -- http://www.lavasoftusa.com

Also, how are your computers connected. Hub or switch?

May be the network media is unreliable.

 

[Kenneth]

On system "A" I did have File and Printer sharing installed and
checked. Because I thought it might be corrupted, I removed it,
rebooted, and then reinstalled it.

Now, I am still unable to open files on system "A" from system "B". I
can open files on "A" from system "C" or "D" however.

This indicates that problem could be in B rather than A.

Also make sure that common username and passwords acounts exist in
the machines.

Everything with regard to Users and Passwords looks fine...
[...]

I shut down the firewall on system "A".

Right now, when I ping system "A" from system "B" by name or by IP
address it succeeds.

I then went to system "A" and tried to ping system "B". When trying by
IP address, it times out. When trying using the name of system "B" it
give "Unknown Host" error.

But then it got more weird.

I went back to system "B" and tried to ping "A" again. Now, ping
succeeds when I enter the IP address of "A", but when I enter the name
of "A" I get "Unknown Host." Absolutely nothing had changed on either
system between these two efforts.

About three minutes later, I tried again. Now, when I ping system "A"
from system "B" by name, or by IP address, it succeeds once again.

Because both versions of pinging "A" succeeded, I tried again to
"open" system "A" by browsing from system "B". I got the now familiar
error "A" is not accessible. The network path was not found.

I then went to system "C" and using exactly the same technique
attempted to browse files on system "A". They opened immediately.

Then, from system "C" I tried to browse system "B" but, to my
surprise, I could not. I got the error "The network path was not
found." Based on my earlier experience, I uninstalled, then
reinstalled File & Printer Sharing. With that, I could browse files on
"B" from "C". Of course, I immediately tried to browse "A" from "B",
but it still does not work. I got the "The network path was not found"
error.

When I try to browse files on "B" from "A" I get the same error.

Very Strange results.

I would suggest you to perform a virus scan and scan for spywares and
adawares.

spyware removal spybot -- http://www.safer-networking.org
Another spyware remove ad-aware -- http://www.lavasoftusa.com

Also, how are your computers connected. Hub or switch?

May be the network media is unreliable.

Hi Madhur,

Your very last comment just above may have been the charm...

Prior to receiving your last message, I experimented with changing the
name of system "A". To my surprise, when I then attempted to look at
the list of systems in the Workgroup from system "B" it listed both
the old name of system "A" and the new name... Neither could be
browsed.

I then saw your comment about "network media" and decided to reset my
router. That meant that in essence, I had to re-install the router.

When I did that, the network list appeared correctly (that is, with
only the current, new, name for system "A") and, it was possible to
browse that system properly!

So, though I hesitate to declare full victory, it does appear that the
problem is now resolved.

As before, please accept my sincere thanks for your skill, and your
generosity.

All the best,

 

[Madhur Ahuja]

So, though I hesitate to declare full victory, it does appear that the
problem is now resolved.

As before, please accept my sincere thanks for your skill, and your
generosity.

All the best,

Glad, the problem is resolved ! Thanks for the feedback.

 

[Kenneth]

Glad, the problem is resolved ! Thanks for the feedback.

Hi Madhur,

Given further experimentation, I think that I am going to replace my
router. I find that I am having problems similar to those we have
discussed, but this time, with another system.

My intuition is that there is something flaky in the router itself.

We shall see...

Thanks again,

 

[Madhur Ahuja]

Hi Madhur,

Given further experimentation, I think that I am going to replace my
router. I find that I am having problems similar to those we have
discussed, but this time, with another system.

My intuition is that there is something flaky in the router itself.

We shall see...

Thanks again,

If your test systems were connected to the network used previously and
if there is no problem with the router, I'll suggest you to go through
a spyware and adware scanner. I have seen some spywares causing the
symptoms you mentioned earlier.

Best of Luck