Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Create a TCP/IP Connection
Top Forums Shell Programming and Scripting Create a TCP/IP Connection Post 302194233 by era on Monday 12th of May 2008 01:36:25 PM
Old 05-12-2008
That one works here, do you get an error message? Maybe your server doesn't run a daytime service on port 13. Mine doesn't, so I get "cannot connect to daytime port", but adapting it to use a port number for which there is a server allows it to work just fine; there is certainly nothing wrong with the code. Changing it to use port 22, for example, it will print the SSH banner from the SSH server (and then nothing, because it obviously doesn't speak that protocol -- that's why they chose daytime, because it uses such a mind-bogglingly stupid, er, I mean, easy-to-understand demo protocol.)

If you don't have previous experience with network protocols, play around with netcat for a while. Maybe it's actually all you will ever need.

Code:
A:\WINDOWS> NETCAT.EXE -l -p 4343

vnix$ nc windows 4343
Stuff I type here will be seen by my Windoze box!
Oh my^C

Last edited by era; 05-12-2008 at 02:42 PM.. Reason: Ctrl-C to break out of netcat
 

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

TCP/IP Connection getting slower...

Hi, We have developed a server program using TCP/IP Communication to communicate with another client program. After running for some days we find the TCP/IP connection from the server program is getting slower. What i mean to say is since the send() function in the server program (it is... (2 Replies)
Discussion started by: rajesh_puru
2 Replies

2. UNIX for Dummies Questions & Answers

How to check the TCP/UDP port of a connection

Hi, Users are connecting thru a KCML Client to UNIX machine, and I want to know which TCP/UDP port that client uses? How can I check the port of a user logged in? Regards, Tayyab (2 Replies)
Discussion started by: tayyabq8
2 Replies

3. UNIX for Advanced & Expert Users

about TCP connection

Hi Experts, need help about release or refresh TCP Connection: i have the sample like below : application log connection: 0500 ( 192.168.0.1:36053) 00919 2007/05/10 23:30:25 112 13 2007/05/10 23:30:25 1969/12/31 17:00:00 0500 ( 192.168.0.1:36054) 00920 2007/05/10 23:30:26 000 00... (3 Replies)
Discussion started by: bucci
3 Replies

4. Programming

close existing tcp connection in C

Hello. I would like to know how to close an existing tcp socket. I have read some stuff and learned how to create a socket and then close it but have not found anything about how to close an existing tcp socket created by another application. The situation is this: I have an ODBC server running and... (6 Replies)
Discussion started by: raidzero
6 Replies

5. Solaris

How to kill the TCP ESTABLISHED connection in netstat

Hello, Actually there are some bugs in application which does not close the TCP connection to other server though CORBA. We need to kill that ESTABLISHED connections as new connection are not happeneing as the allocated ports were used and showing as ESTABLISHED Is there any... (4 Replies)
Discussion started by: GIC1986
4 Replies

6. UNIX for Dummies Questions & Answers

TCP failed connection attempts from netstat -s

Dear experts, I am seeing a lot of TCP failed connection attempts from "netstat -s" on one of our servers. How can I pin point what connection failed and what are the ports involved? Any tools/commands I can dig in deeper to diag. what went wrong on these "failed connection attempts"? ... (2 Replies)
Discussion started by: cache51
2 Replies

7. IP Networking

false tcp connection

Why this happens? How to solve this? $netstat -na |grep 9325 tcp 0 0 127.0.0.1:9325 127.0.0.1:9325 ESTABLISHED When a client socket repeatedly tries to connect to an inactive(no server socket is listening on this port) local port,connect succeeds. ... (1 Reply)
Discussion started by: johnbach
1 Replies

8. Solaris

many tcp connection in close-wait

Hi, I use solaris Unix . I find there is some problem in application and it generate many "close-wait" tcp connect and stay in the server . it is generate by process id 7740 root@XX # netstat -an | grep CLOSE_WAIT | wc -l 285 root@XX # netstat -an | grep CLOSE_WAIT 10.158.35.4.34805 ... (2 Replies)
Discussion started by: abcdef
2 Replies

9. Programming

TCP connection check

Hi. I am writing client - server application using TCP sockets. I need some very basic functionality, namely: how to check if another "participant" of the connection is still present? I want to handle situations, when client is gone, or server breaks down, etc. (25 Replies)
Discussion started by: Shang
25 Replies

10. UNIX for Dummies Questions & Answers

Tcp connection to Linux server fails

I am trying to send json messages to a port on a linux server from a remote server running a .net program. I have one implementation running with successful incoming messages to port 1514. I tried to replicate the same thing but just to another port but cannot get it to work as I get the following... (3 Replies)
Discussion started by: unienewbie
3 Replies

LEARN ABOUT ULTRIX

tcp-env

tcp-env(1)                                                    General Commands Manual                                                   tcp-env(1)

NAME

       tcp-env - set up TCP-related environment variables

SYNOPSIS

       tcp-env [ -rR ] [ -ttimeout ] program [ arg ...  ]

DESCRIPTION

       The  input  for  tcp-env  must be a TCP connection.  tcp-env finds out information about that connection, puts the information into several
       environment variables as described in tcp-environ(5), and runs program with the given arguments.

       Usually tcp-env is run from inetd.  It might instead be run from another server that already sets up the right  environment  variables;  if
       PROTO  is  set  to  TCP  when  tcp-env  is invoked, tcp-env assumes that all the other variables are set up properly, and it does not check
       whether the input is a TCP connection.

OPTIONS

       -r     (Default.)  Attempt to obtain TCPREMOTEINFO from the remote host.

       -R     Do not attempt to obtain TCPREMOTEINFO from the remote host.

       -ttimeout
              Give up on the TCPREMOTEINFO connection attempt after timeout seconds.  Default: 30.

SEE ALSO

       tcp-environ(5), inetd(8)

                                                                                                                                        tcp-env(1)
All times are GMT -4. The time now is 09:15 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy