Re: Making a TCP or UDP or Unux Socket Server Listen on a port

[<shyamk@eth.net>]

Yesterday , I was speaking about a nteworking program (client-server) , , client
running on 10.10.1.15
and server (prog.) running on 10.10.1.4

I am very grateful for the generous help of  suggestions ,
I received from all.

Well this is the current situation :-

1) I  started the server program at 10.10.1.4
2)   I did  netstat -an|grep 9888       at  10.10.1.4 and received the following
information    :-
         [shyam@ 10.110.1.4 shyam] $ netstat -an|grep 9888
         tcp    0    0  0.0.0.0.9888    0.0.0.0.*    LISTEN

3) I also tried from the  (supposed  client mac) 10.10.1.1.        :-
      telnet  10.10.1.4  23
     & I am getting connected .
4) Now on 10.10.1.15      , I start  the client program  and  try netstat on the
server (10.10.1.4)
    [shyam@10.10.1.4 shyam] $ netstat -an|grep 9888
    tcp    0    0  10.10.1.4:9888    10.10.1.15:1025    ESTABLISHED
    tcp     0    0  0.0.0.9888          0.0.0.0:*                LISTEN
5) Now the client (10.10.1.15) types in some message  that is
  supposed to go to the server. and this is where my problems start :

  The program  has been written such that , once the server sitting at 10.10.1.4  and
  listening at 9888  , gets what the client has typed , ( which I do not see on the
server prog's
  console)  , the server flashes a reply back to the client (and he is supposed to
see that)

BUT , neither the message  typed by the client on his console , nor the message
 typed by the server on his console , get displayed on the other's console !


I reason out two possible causes : -
1) a) Maybe , programmatically , I need to indicate EOL  or EOT ,  on each side
    to show that each has completed his writing and to finally send it .
    b) May be , the programs have not handled  input/output properly .
.
2) May be, the data  may not be moving across the wire .

But when I checked things out , I do not find  reasons  for suspecting the program.

Should I attach the server(tcp) and the client(tcp) ?

Thanks for all help,
(shyamk@eth.net)
Shyam

----- Original Message -----
From: "Dmitriy Kropivnitskiy" <jeld@mindless.com>
To: <shyamk@eth.net>; <debian-user@lists.debian.org>
Sent: Saturday, November 17, 2001 2:01 AM
Subject: Re: Making a TCP or UDP or Unux Socket Server Listen on a port


Can your systems ping each other?

On Thursday 15 November 2001 11:35 am, shyamk@eth.net wrote:
> I am having  Server Programs (for TCP,UDP,Unix Sockets) , that listen on a
> port number say , 9888 at
> 10.10.1.4
> and they are being contacted by a Client (for TCP,UDP,Unix Sockets)  Linux
> machine from 10.10.1.1 .
>
> Both macines are on the LAN , nothing more nothing less . We have not yet
> gone for any higher stuff like DNS , etc . So , basically  10.10.1.4
> and 10.10.1.1 are not on any Linux network , but simply they identify and
> respond on the LAN.
>
> My Clients and Server (socket  programs) do not communicate at all on this
> network .
>
> Please guide me on what I should do .
>
> My line of thinking is : Add some  entry to the
> /etc/services   specifying the port , but this is what I tried and failed
> :- # At the bottom of /etc/services  :-
> tcp 9888/tcp
> a.out 9889/tcp
>
> Please help me get these programs to communicate .
>
> Warm regards,
> (shyamk@eth.net)
> Shyam