One-Way Communication

[Barefoot_Tom]

I have 2 computers linked in a network. One computer uses WIN98SE, the other WIN2000. Until recently I was able to message the computers; using WINPOPUP.EXE from the WIN98 computer, and Net Send from the other.

Suddenly, I am only able to communicate 1-way. I can send a message from the WIN2000 computer and it will be received by the other, but the reverse doesn't work.

Each computer recognizes the other as part of the network; they are both part of the same Workgroup; and I can ping each computer from the other. I can share files, etc. with no problems.

I am using ZoneAlarm as my firewall, and if  I turn it off, I can communicate 2-ways. The problem seems to lie with the ZoneAlarm settings on the WIN2000 computer. I have checked the firewall connections in the ZoneAlarm program, and I have, in both cases, the other computer's IP address as being in the "Trusted Zone". Nevertheless, the WIN2000 computer can neither send nor receive messages. The WIN98 computer indicates, though that the message has been successfully sent when I send from it.

Any ideas?
Tom
Tom

[Barefoot_Tom]

Correction & Resolution

My initial analysis of the problem led me to believe ZoneAlarm was involved. It apparently was not. I found the WIN2000 computer would not receive or display messages whether ZoneAlarm was active or not.

I went to Microsoft's knowledge base, and found an article which said that in WIN2000 Net Send had a message queue which held a maximum of 6 messages. In order for the messages not be queued they had to be removed as they were received. After 6 messages Net Send would neither acknowledge nor display any further messages. This was the situation I was apparently seeing. The article did not, however, give any information as to how the queue could be cleared.

Finally, I re-booted the WIN2000 computer, and (for the moment at least) I am back to 2-way communication.
Tom

[Geek-9pm]

The use of NET SEND is not in Windows VISTA and the MS KB says that

By default, the NET SEND command fails when either the source or the destination computer is running Windows XP Service Pack 2

That being the case. you may have got a recently security update for Windows 2000 that also turns off the messenger service, or something like that.
Anyway, there are other ways to send messages.

[Barefoot_Tom]

The use of NET SEND is not in Windows VISTA ...............
That being the case. you may have got a recently security update for Windows 2000 that also turns off the messenger service, or something like that.
Anyway, there are other ways to send messages.

No, I have nothing to do with VISTA, and I didn't get the wrong security update.
So far as other ways of sending messages, I suppose I could use semaphore, but that's hardly efficient. The purpose of trying to find the reason for a malfunction is two-fold: first, so that corrections can be made, and second; to learn more about the system. If something works, and then suddenly doesn't work, there is a reason for this happening. Finding that reason is important. Doing something else really doesn't solve the problem, does it?
Tom

[Geek-9pm]

Simple answer is that a early message service is a security risk. It can be turned off in services. You or a program turned off the service. I think that is what you are talking about. Here is a link. 
http://itc.virginia.edu/helpdesk/softwaredocs/messagepopup/
This is NOT the same as Yahoo messenger or other IM programs.

[Barefoot_Tom]

  You or a program turned off the service. I think that is what you are talking about. 

Thanks for the response, but that was not the problem, nor did the link you provided yield any insight. Since I eliminated the message queue, as I said above, I have experienced no problems. The service was never turned off; neither by me nor a program.
Tom