473,728 Members | 2,103 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

Reusing a local address/port when creating sockets that send data


I want to periodically send a TCP packet to a peer, always from the same
source port. That is, each packet will come from my local ip address, port
8801, and go to the peer's ip address, to HIS port 8801.

This means that I need to bind my sender socket to (myaddress,8801 ), use it
for the send, then shut it down and close it. Then I want to wait, say 30
seconds, and do it all over again. Naturally, the socket's ReuseAddress
property must be set for this to work.

However, in practice, the second time I bind a socket to my local endpoint,
I get a SocketException : "Only one usage of each socket address
(protocol/network address/port) is normally permitted."

Can anyone help me? The following code attempts to send a string containing
the date/time to a server on 10. If I set the "bindIt"
variable to false, the code works fine. If I try to bind (and re-bind) the
socket to the same local endpoint (e.g, I've set bindIt to true), the code
fails with the above exception. Help!


Greg Hassett

using System;
using System.IO;
using System.Net;
using System.Net.Sock ets;
using System.Text;
using System.Threadin g;

class TcpClientTest
static public void Main()
bool bindIt = true;

IPHostEntry localHostEntry = Dns.GetHostByNa me(Dns.GetHostN ame());
IPEndPoint localIPEndPoint = new IPEndPoint
(localHostEntry .AddressList[0], 8801);

while (true)
Console.WriteLi ne("Press return to send data");
Console.ReadLin e();

Socket socket = new Socket(AddressF amily.InterNetw ork,
SocketType.Stre am, ProtocolType.Tc p);

socket.SetSocke tOption (SocketOptionLe vel.Socket,
SocketOptionNam e.ReuseAddress, 1);
socket.SetSocke tOption (SocketOptionLe vel.Socket,
SocketOptionNam e.Linger, new LingerOption(fa lse, 0));
socket.SetSocke tOption (SocketOptionLe vel.Socket,
SocketOptionNam e.DontLinger, 1);

if (bindIt)
socket.Bind (new IPEndPoint (IPAddress.Any, 8801));

socket.Connect (new
IPEndPoint(IPAd dress.Parse("19"), 8801));

byte[] buf = Encoding.ASCII. GetBytes
(DateTime.Now.T oString());
socket.Send (buf);

socket.Shutdown (SocketShutdown .Both);
socket.Close ();

Console.Out.Wri teLine ("Sent");
catch (Exception ex)
Console.Out.Wri teLine (ex.ToString()) ;

Nov 17 '05 #1
0 3024

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

by: Jo Voordeckers | last post by:
Hello all, I'm pretty new to the Java newsgroups so I apologize for dropping this into several maybe offtopic groups. I'm sorry! So on to my problem... I've come to a point in our RMI application where I need to have server callbacks to the client RMI applications. I've used the technique where the client passes an UnicastRemoteObject of itself to a RMI server method that registers the clientinterface object in a Vector. Now when I do...
by: John Morgan | last post by:
I have Enterprise Manager on my local machine. For the last twelve months it has been connecting without problem to my online SQL Server database provided by my ISP. Three weeks ago the ISP applied some sort of extra security arrangements to their SQL Server to allow access only through port 1433. they have told me to configure an alias using Network Client and to register this alias in the usual way using my Enterprise Manager. My...
by: Rex Winn | last post by:
I've Googled until my eyes hurt looking for a way to issue Telnet commands from C# and cannot find anything but $300 libraries that encapsulate it for you. I don't want to be able to create a Telnet client. I just need to send a telnet request to a local IP address on a LAN issue a "c" then a "b" and stream back the text for internal use. The "c" changes sub-menus and the "b" is a switch to dump the status of a firewall. I need to issue...
by: D. André Dhondt | last post by:
In VB.NET 2003, is there a way to create a System.Net.Sockets.UDPClient to listen to any address AND any port? I can get it to listen to any address, but only if I specify a port (for example, port 12345): '----------- Dim udpClient as New Sockets.UdpClient(12345) Dim ipEndPoint as New IPEndPoint(IPAddress.Any, 0) Dim receiveBytes as Byte()
by: Marty | last post by:
Hi, When we create a new socket and make it connect to a remote endpoint, how can we tell to the socket to use a specific IP address on the local computer, when multiples IPs are enabled. Thank you Marty
by: Sharon | last post by:
Hi all, I've implemented a TCP server using the Socket async methods. When connecting to the server from 3 instances of hyper terminal, i've noticed that each of the newly created server sockets, uses the same server port. I assumed that a new connection will receive a unique port. If this is the way its suppose to work, is it a performance issue? Is it possible that connections from the same IP will connect on the same server port? I...
by: jasonsgeiger | last post by:
From: "Factor" <jasonsgeiger@gmail.com> Newsgroups: microsoft.public.in.csharp Subject: Multiple Clients, One port Date: Wed, 19 Apr 2006 09:36:02 -0700 I'm been working with sockets for a short while now using a server program a former coworker started. The program listens on a port for incomming connections. When a valid connection is made (we send this init string into the socket from the clients) the server closes the socket so...
by: jcprince | last post by:
Hi Not sure I can do what I'm trying to do without using a 3rd party component like Dart. I need to build a windows service to create a socket connection on an IBM mainframe using an IP and port combination. No problem there. However, due to the expected volume (at least 20x10K streams per second in each direction), the mainframe sysadmin has requested the service use multiple 'conversations' within the single IP connection. The...
by: Xionbox | last post by:
Hello everybody, The error I have seems very easy to solve, but for some odd reason I can't seem to solve it. Anyways, here's my "setup". I created a server running on localhost:1200 (telnet localhost 1200 proves that it is up and running) and I coded a client which is supposed to connect to that server and send it data. The odd part is that the client connects to the server (via connect()) without any problem, but three lines later, it...
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look ! Part I. Meaning of...
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it. First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own.... Now, this would greatly impact the work of software developers. The idea...
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules. He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms. Adolph will...
by: TSSRALBI | last post by:
Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
by: 6302768590 | last post by:
Hai team i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
by: bsmnconsultancy | last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.