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by Mike van Bokhoven >> Wed, 5 Jan 2000 4:43:42 GMT

Hi all,

Just a quick question about some strange TCP/IP behaviour.

A short time ago, I wrote a simple listen server, using Jade's TcpIpConnection class. This worked fine; I initially tested it on Win98, using the Telnet client as the client, then later, writing my own client in Jade.

I have now upgraded to Windows 2000 RC2, and find that this no longer behaves as it used to. My Jade client, run from the same node as the server, still connects fine to 127.0.0.1, but will no longer connect to my external IP address. And, if I start another Jade node on the same machine, neither 127.0.0.1 nor my external IP address respond to the client. Similarly, Telnet simply responds with 'Connect Failed' to either. NT4 behaves identically to 2000. A test on a Win98 machine verifies that everything still works fine in that situation.

So, my question is: Does anyone know why this is happening? It appears that there is some difference in the behaviour of TCP/IP between Windows 98 and NT4/Windows 2000 as far as Jade is concerned. If someone is able to shed some light on this, I'd be very grateful.


Mike.

by Rob E >> Thu, 6 Jan 2000 4:32:59 GMT

Hi Mike,

I am working on Windows 2000 RC2 and NT4SP3 and I have no problems.
From the fact that both JADE and Telnet appear to have a problem connecting to the host, of which presumably you supplied the hostname, I would suggest that DNS on your newly installed OS environment may be the problem.

If you do not use DNS you may have lost the contents of %winroot%\system32\drivers\etc\hosts during the upgrade. On Windows 2000 RC2 this file only contains one entry for "127.0.0.1 localhost".

Before attempting to connect from either JADE or Telnet, make sure you can ping the target host from a DOS command line, using the taget host's IP address. If this works OK, then ping the target host again, using the hostname.

I hope this is useful for you,

Rob.

by Mike van Bokhoven >> Thu, 6 Jan 2000 22:12:21 GMT

I am working on Windows 2000 RC2 and NT4SP3 and I have no problems. From the fact that both JADE and Telnet appear to have a problem connecting to the host, of which presumably you supplied the hostname, I would suggest that DNS on your newly installed OS environment may be the problem. Before attempting to connect from either JADE or Telnet, make sure you can ping the target host from a DOS command line, using the taget host's IP address. If this works OK, then ping the target host again, using the hostname.

Unfortunately, in my case, it's not so simple; I am using solely IP addresses, and only those of my own machine. This is what I find strange - the difference in behaviour between 127.0.0.1 and the 'real' IP address of my machine. My understanding was that they should behave identically, and are simply two different aliases for the same interface.

Pinging both succeeds - both are of course local IP addresses. TCP/IP seems to run fine otherwise.

Thanks for the info - now at least I know there's nothing particularly nasty about TCP/IP on Win2000 / NT. Perhaps there's something strange or incorrect in the way I'm setting up and using TcpIpConnection.


Mike.