Search Results

Search found 3538 results on 142 pages for 'tcp hijacking'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 8/142 | < Previous Page | 4 5 6 7 8 9 10 11 12 13 14 15  | Next Page >

  • Can an application affect TCP retransmits

    - by sipwiz
    I'm troubleshooting some communications issues and in the network traces I am occasionally coming across TCP sequence errors. One example I've got is: Server to Client: Seq=3174, Len=50 Client to Server: Ack=3224 Server to Client: Seq=3224, Len=50 Client to Server: Ack=3224 Server to Client: Seq=3274, Len=10 Client to Server: Ack=3224, SLE=3274, SRE=3284 Packets 4 & 5 are recorded in the trace (which is from a router in between the client and server) at almost exactly the same time so they most likely crossed in transit. The TCP session has got out of sync with the client missing the last two transmissions from the server. Those two packets should have been retransmitted but they weren't, the next log in the trace is a RST packet from the Client 24 seconds after packet 6. My question is related to what could be responsible for the failure to retransmit the server data from packets 3 & 5? I would assume that the retransmit would be at the operating system level but is there anyway the application could influence it and stop it being sent? A thread blocking or put to sleep or something like that?

    Read the article

  • .NET TCP Client/Server communication issue

    - by Jamie
    What I'm currently trying to do is make a very basic webchat for irc using silverlight. Basically how I'm trying to do it is have a tcp server listening for connections from silverlight. When a client connects it creates a new connection to irc and data is passed to/from the client/irc via the server application. I've gotten it to work fine for one client connection, but as soon as two (or more) clients connect multiple connections are made to irc but all data passed from the clients just goes through the latest irc connection (if that makes sense). For example Client1, Client2 and Client3 are all connected to irc, but no matter who sends data it all comes through Client3. Between the client and server app it recognizes the data coming in from different clients so i believe the problems lies within the way I've connected to the irc. When the TCP server accepts a new client a new thread is made to listen to incoming data, and from there a new thread is made to connect to irc. I'm sure thats where the problem exists, but I've confused myself a lot now and am wondering if anyone can help me figure out a solution. EDIT: What I think is the problem, is that it can't distinguish which thread the specific client is using, so it just sends it via the latest one. Can this even be done?

    Read the article

  • TCP Socket.Connect is generating false positives

    - by Mark
    I'm experiencing really weird behavior with the Socket.Connect method in C#. I am attempting a TCP Socket.Connect to a valid IP but closed port and the method is continuing as if I have successfully connected. When I packet sniffed what was going on I saw that the app was receiving RST packets from the remote machine. Yet from the tracing that is in place it is clear that the connect method is not throwing an exception. Any ideas what might be causing this? The code that is running is basically this IPEndPoint iep = new IPEndPoint(System.Net.IPAddress.Parse(m_ipAddress), m_port); Socket tcpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); tcpSocket.Connect(iep); To add to the mystery... when running this code in a stand alone console application, the result is as expected – the connect method throws an exception. However, when running it in the Windows Service deployment we have the connect method does not throw an exception. Edit in response to Mystere Man's answer How would the exception be swallowed? I have a Trace.WriteLine right above the .Connect method and a Trace.WriteLine right under it (not shown in the code sample for readability). I know that both traces are running. I also have a try catch around the whole thing which also does a Trace.Writeline and I don't see that in the log files anywhere. I have also enabled the internal socket tracing as you suggested. I don't see any exceptions. I see what appears to be successful connections. I am trying to identify differences between the windows service app and the diagnostic console app I made. I am running out of ideas though End edit Thanks

    Read the article

  • TCP Message Structure with XML

    - by metdos
    Hello Everybody, I'm sending messages over TCP/IP and on the other side I parse TCP message.For example this is one of the sent messages. $DKMSG(requestType=REQUEST_LOGIN&requestId=123&username=metdos&password=123)$EDKMSG Clarification: $DKMSG( //Start )$EDKMSG //End requestType //Parameter REQUEST_LOGIN //Parameter Value Now I also want to add an Xml file to my message. I'm considering this option: $DKMSG(requestType=REQUEST_LOGIN&xmlData= <Item id="56D@MIT" type="SIGNAL"> <Label> <Text>56D</Text> <X1>10</X1> <Y1>40</Y1> <RotateAngle>90</RotateAngle> </Label> <X1>0</X1> <Y1>20</Y1> <Width>35</Width> <Height>10</Height> <Source>sgs3lr</Source> </Item> )$EDKMSG There are problems with this way: 1-)It doesn't seem right to me. 2-)I have to handle delimeter "=" with much more care or I need to change it in parameters. What are your suggestions, thanks.

    Read the article

  • Perl TCP Server handling multiple Client connections

    - by Matt
    I'll preface this by saying I have minimal experience with both Perl and Socket programming, so I appreciate any help I can get. I have a TCP Server which needs to handle multiple Client connections simultaneously and be able to receive data from any one of the Clients at any time and also be able to send data back to the Clients based on information it's received. For example, Client1 and Client2 connect to my Server. Client2 sends "Ready", the server interprets that and sends "Go" to Client1. The following is what I have written so far: my $sock = new IO::Socket::INET { LocalHost => $host, // defined earlier in code LocalPort => $port, // defined earlier in code Proto => 'tcp', Listen => SOMAXCONN, Reuse => 1, }; die "Could not create socket $!\n" unless $sock; while ( my ($new_sock,$c_addr) = $sock->accept() ) { my ($client_port, $c_ip) = sockaddr_in($c_addr); my $client_ipnum = inet_ntoa($c_ip); my $client_host = ""; my @threads; print "got a connection from $client_host", "[$client_ipnum]\n"; my $command; my $data; while ($data = <$new_sock>) { push @threads, async \&Execute, $data; } } sub Execute { my ($command) = @_; // if($command) = "test" { // send "go" to socket1 print "Executing command: $command\n"; system($command); } I know both of my while loops will be blocking and I need a way to implement my accept command as a thread, but I'm not sure the proper way of writing it.

    Read the article

  • Benefits of "Don't Fragment" on TCP Packets?

    - by taspeotis
    One of our customers is having trouble submitting data from our application (on their PC) to a server (different geographical location). When sending packets under 1100 bytes everything works fine, but above this we see TCP retransmitting the packet every few seconds and getting no response. The packets we are using for testing are about 1400 bytes (but less than 1472). I can send an ICMP ping to www.google.com that is 1472 bytes and get a response (so it's not their router/first few hops). I found that our application sets the DF flag for these packets, and I believe a router along the way to the server has an MTU less than/equal to 1100 and dropping the packet. This affects 1 client in 5000, but since everybody's routes will be different this is expected. The data is a SOAP envelope and we expect a SOAP response back. I can't justify WHY we do it, the code to do this was written by a previous developer. So... Are there are benefits OR justification to setting the DF flag on TCP packets for application data? I can think of reasons it is needed for network diagnostics applications but not in our situation (we want the data to get to the endpoint, fragmented or not). One of our sysadmins said that it might have something to do with us using SSL, but as far as I know SSL is like a stream and regardless of fragmentation, as long as the stream is rebuilt at the end, there's no problem. If there's no good justification I will be changing the behaviour of our application. Thanks in advance.

    Read the article

  • [java] tcp socket communication [send and recieve help]

    - by raven
    hello, I am creating a Chat in java. I have a method (onMouseRelease) inside an object that creates a tcp server and waits for a socket ServerSocket server = new ServerSocket(port); Socket channel = server.accept(); now I want to make a thread that will loop and read data from the socket, so that once the user on the other side sent me a string, I will extract the data from the socket [or is it called packet? sry I am new to this], and update a textbox to add the additional string from the socket [or packet?]. I have no idea how to READ (extract) the information from the scoket [/packet] and then update it into a JTextArea which is called userOutput. And how to Send a string to the other client, so that it will also could read the new data and update its JTextArea. (from what I know, for a 2 sided tcp communication you need one computer to host a server and the other to connect [as a client] and once the connection is set the client can also recieve new information from the socket. Is that true? and please tell me how ) Any help appreciated !! I know this is abit long but I have searched allot and didn't understand [I saw something like printwriter but failed to understand].

    Read the article

  • TCP socket communication

    - by raven
    hello, I am creating a Chat in java. I have a method (onMouseRelease) inside an object that creates a tcp server and waits for a socket like this: ServerSocket server = new ServerSocket(port); Socket channel = server.accept(); Now I want to make a thread that will loop and read data from the socket, so that once the user on the other side sends me a string, I will extract the data from the socket (or is it called packet? Sorry, I am new to this) and update a textbox to add the additional string from the socket (or packet?). I have no idea how to READ (extract) the information from the socket(/packet) and then update it into a JTextArea which is called userOutput. And how to send a string to the other client, so that it will also could read the new data and update its JTextArea. From what I know, for a 2 sided TCP communication you need one computer to host a server and the other to connect (as a client) and once the connection is set the client can also receive new information from the socket. Is that true? and please tell me how. Any help is appreciated! I know this is a bit long but I have searched a lot and didn't understand it (I saw something like PrintWriter but failed to understand).

    Read the article

  • TCP multicast and multithreading

    - by Fantastic Fourier
    I need to come up with clients that can multicast to other clients reliably. That implies I'll be using TCP to connect reliably between clients within a multicast group. Doesn't that come up to n^2 number of connections? That seems a little silly to me. Wouldn't/shouldn't there be a way to more easily multicast with reliability?

    Read the article

  • C# TCP socket and binary data

    - by MD
    Hi @All How to send binary data (01110110 for exemple) with C# throught a TCP (using SSL) socket ? I'm using : SslStream.Write() and h[0] = (byte)Convert.ToByte("01110110"); isn't working Thanks.

    Read the article

  • how to reassemble tcp segment?

    - by jerams
    im now developing a project using winpcap..as i have known packets being sniffed are usually fragmented packets. how to reassemble this TCP segements?..any ideas, suggestion or tutorials available?.. this i assume to be the only way i can view the HTTP header... thanks!..

    Read the article

  • Not receiving all message via TCP in Java?

    - by javatcp
    I have a tcp socket sending three lines like this out2.println("message1\n"); out2.println("message2\n"); out2.println("message3\n"); and another tco socket receiving and displaying these messages like this System.out.println(in.readLine()); System.out.println(in.readLine()); System.out.println(in.readLine()); but only the first message is recieved and displayed, anything I send after that is not.

    Read the article

  • Establishing a tcp connection from within a DLL

    - by Nicholas Hollander
    I'm trying to write a piece of code that will allow me to establish a TCP connection from within a DLL file. Here's my situation: I have a ruby application that needs to be able to send and receive data over a socket, but I can not access the native ruby socket methods because of the environment in which it will be running. I can however access a DLL file and run the functions within that, so I figured I would create a wrapper for winsock. Unfortunately, attempting to take a piece of code that should connect to a TCP socket in a normal C++ application throws a slew of LNK2019 errors that I can not for the life of me resolve. This is the method I'm using to connect: //Socket variable SOCKET s; //Establishes a connection to the server int server_connect(char* addr, int port) { //Start up Winsock WSADATA wsadata; int error = WSAStartup(0x0202, &wsadata); //Check if something happened if (error) return -1; //Verify Winock version if (wsadata.wVersion != 0x0202) { //Clean up and close WSACleanup(); return -2; } //Get the information needed to finalize a socket SOCKADDR_IN target; target.sin_family = AF_INET; //Address family internet target.sin_port = _WINSOCKAPI_::htons(port); //Port # target.sin_addr.s_addr = inet_addr(addr); //Create the socket s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (s == INVALID_SOCKET) { return -3; } //Try connecting if (connect(s, (SOCKADDR *)&target, sizeof(target)) == SOCKET_ERROR) { //Failed to connect return -4; } else { //Success return 1; } } The exact errors that I'm receiving are: Error 1 error LNK2019: unresolved external symbol _closesocket@4 referenced in function _server_disconnect [Project Path] Error 2 error LNK2019: unresolved external symbol _connect@12 referenced in function _server_connect [Project Path] Error 3 error LNK2019: unresolved external symbol _htons@4 referenced in function _server_connect [Project Path] Error 4 error LNK2019: unresolved external symbol _inet_addr@4 referenced in function _server_connect [Project Path] Error 5 error LNK2019: unresolved external symbol _socket@12 referenced in function _server_connect [Project Path] Error 6 error LNK2019: unresolved external symbol _WSAStartup@8 referenced in function _server_connect [Project Path] Error 7 error LNK2019: unresolved external symbol _WSACleanup@0 referenced in function _server_connect [Project Path] Error 8 error LNK1120: 7 unresolved externals [Project Path] 1 1 Many thanks!

    Read the article

  • how to send an array of bytes over a TCP connection (java programming)

    - by Mark Roberts
    Can somebody demonstrate how to send an array of bytes over a TCP connection from a sender program to a receiver program in Java. (I'm new to Java programming, and can't seem to find an example of how to do this that shows both ends of the connection (sender and receiver.) If you know of an existing example, maybe you could post the link. (No need to reinvent the wheel.) P.S. This is NOT homework! :-)

    Read the article

  • TCP sequence number question

    - by Meta
    This is more of a theoretical question than an actual problem I have. If I understand correctly, the sequence number in the TCP header of a packet is the index of the first byte in the packet in the whole stream, correct? If that is the case, since the sequence number is an unsigned 32-bit integer, then what happens after more than FFFFFFFF = 4294967295 bytes are transferred? Will the sequence number wrap around, or will the sender send a SYN packet to restart at 0?

    Read the article

  • WCF TCP Protocol

    - by jobless-spt
    I want to host a WCF service with TCP Protocol. I can host the service using IIS or Windows Service. I need to know what port I need to open for this service for it to be accessible by client?

    Read the article

  • python send/receive hex data via TCP socket

    - by Mike
    I have a ethenet access control device that is said to be able to communicate via TCP. How can i send a pachet by entering the HEX data, since this is what i have from their manual (a standard format for the communication packets sent and received after each command)

    Read the article

  • Linux tool to send raw data to a TCP server

    - by paul simmons
    Hi, I am aware that this is not a direct 'development' question but I need that info to test a development project, so I think someone could've hit similar problem. I will test a software that runs a TCP server and according to sent commands replies some answers. I will test the software and do not want to write code if it doesn't work well. So I want to send those commands and test drive the server software. How can I achieve this with a Linux box?

    Read the article

  • Close an external TCP connection

    - by oidfrosty
    How can i terminate a tcp connection wich is not handled by my program? for example i want to close all the connection on port 10202 and i dont want them to reopen but i want to allow the other ports everything in C# like Sysinternals' tcpView does

    Read the article

  • TCP Connection Persistent State

    - by TripShock
    Is there any field/option/anything that I can put in a TCP packet (be it a syn or an ack or just plain data) that I can be sure will be returned by the other end intact? For eg. I want to "tag" a particular connection (src, srcport, dst, dstport) with a number that I can always read from a packet belonging to that connection. That means I can identify the connection without using the 4-tuple (as given above).

    Read the article

  • Transmitting complex objects using TCP

    - by Rakesh K
    I have a client server application in which I need to transmit a user defined object from Client to Server using TCP connection. My object is of the following structure: class Conversation { private string convName, convOwner; public ArrayList convUsers; public string getConvName() { return this.convName; } public string getConvOwner() { return this.convOwner; } } Please help me how to transmit this object at from client and again de-serialize it into appropriate object at server side.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 4 5 6 7 8 9 10 11 12 13 14 15  | Next Page >