Questions tagged [tcp]
TCP stands for Transmission Control Protocol and is one of the core protocols of the Internet Protocol Suite. TCP complements the Internet Protocol (IP), and therefore the entire suite is commonly referred to as TCP/IP.
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TCP/IP minimal size
I am using a high level language on a PC to send a message via TCP/IP to a remote device which is an embedded device.
I am sending relatively small messages (< 255 bytes).
I must assume that there ...
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Why does writing IP addresses this alternate way work, and is there a practical use case for it? [duplicate]
Recently I saw an incorrectly typed telnet command, and I saw that "regular" numbers were interpreted to IP addresses. I tried this myself in Windows and the same behavior is shown there, so obviously ...
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Free official documentation for cables and models? [closed]
I've been looking through the ISO and IEEE sites for official documentation on the Open Systems Interconnection (OSI) model, TCP, and a range of cable standards (5/5e/6). However, other than on the ...
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Is DNS query a UDP or TCP?
I know that when we first type an address on the URL and enter. The DNS query starts. I don't who initiates, but my guess is application will only initiate the DNS query. The DNS query already knows ...
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What impacts does RTT have on the behaviour of TCP?
How does round-trip time impact a TCP connection's behaviour? I know that the throughput of a connection with a high RTT is lower than the throughput of a connection with a low RTT but how does RTT ...
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How to calculate TCP network speed
So basically this is an easy question, but not an easy answer.
How do i calculate the download and upload speed in order to make program this in c#?
I'm not sure how to take latency into account.
I ...
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Communication possible between 192.168.0.x and 192.168.1.x?
I have a problem I encounter on a regular basis. I have an access point with a fixed 192.168.0.x IP address. My network is 192.168.1.x. The problem is when I plug the access point into my network, it ...
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Linux Kernel TCP socket functions
So I have been looking through the Linux Kernel v3.8.0-19-generic source code and I noticed that the proto struct, whose members are virtual functions for socket operations depending on the particular ...
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Throughput decreases after MTU 5000
I am trying to test throughput between two computers directly connected through 1 GbE and testing with iperf. I am getting a throughput around 980Mbps when MTU is between 5000 and 5050, however it ...
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Why TCP performance degrade with bidirectional traffic?
I've made a simple experiment on TCP transportation performance. The experiment is as follows:
There are two machines, A and B, each installed with Ubuntu 12.04 Server. I've installed "iperf" on ...
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Is it possible to create a WiFi TCP socket between two computers in a LAN?
Here is our setup.
The FEZ Cobra II (WiFi) Single Board Computer
with a RS9110-N-11-22-04 WiFi module
and running the .NETMF 4.2
The documentation says that:
This allows for real "Socket" ...
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Can using UDP and OpenVPN lead to file corruption?
I know with TCP that it always checks your files to ensure nothing got fragmented or lost or destroyed.
So if I use UDP for OpenVPN to download files or access an internal network, does that mean I ...
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Capture packets from other machines in local network
Is it possible to capture packets from other local machines on my Mac? They are primarily all wireless as well, if that makes it any easier.
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Delete Hung TCP Sessions with SNMP
What I am trying to do, and failing horribly, is to close a TCP connection... I am trying to do this via SNMP and the functionality that is provided in the TCP MIB.
First, I look at all the ...
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Windows 7 / PuTTY drop IPv6 TCP connections on brief outages
This is an IPv6-version of the following question:
Why Windows 7 / PuTTY drop TCP connections even on very brief outages?
After moving from IPv4 to IPv6, I've noticed that my IPv6 connections would ...
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What's up with port 8080 on my OSX box?
I thought a web server process I brought up was listening on localhost:8080, and tried to connect to it, but kept getting connection reset errors. As it turns out, I was mistaken and my process was ...
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how to kill a tcp connection in solaris operating system?
A client program connects to my server program written in JAVA via TCP connection (ServerSocket). I want to close the TCP connection between these two programs with a Solaris command or tool for ...
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No response received from github ssh randomly
My git pull started to stop working randomly with this error
$ git pull
ssh: connect to host github.com port 22: Connection timed
out fatal: The remote end hung up unexpectedly
I tried debugging git ...
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TCP/IP resets (Linux, SSH, RDP, ADSL router)
I have an ADSL router (model Pirelli DR A226G) that seems to cause dropped tcp/ip connections (not ADSL connection per se). I have tracked it using Wireshark and captured a few cases and they always ...
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Does TCP verify data all at once or as a packet by packet verification?
I know that TCP uses verification to ensure accuracy of data by sending to the server. My question is does it verify everything at once or as it comes in?
Quick Example:
Let's say I am loading the ...
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SYN-ACK not received
On a standard TCP connection between server and client, I have this issue: the SYN-ACK is not received from the client, while it is sent from the server. I could see this on Wireshark from both server ...
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Network issues, resolving host
My network connection randomly drops for a 5 minutes or so when I'm online. It always happens when I boot up my computer. I can tell because it says:resolving host in Chrome and I can't ping any ...
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How to configure the physical machine and virtual machine?
If I want to transfer data between the physical machine (windows operating system) and virtual machine (Linux real time operating system). Could anyone please explain about configuring the data ...
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How does an ADSL modem tell which local client to associate with each response from a server?
Does an ADSL modem generate a random string for each request I make and when response comes it directs it to my computer (but not to my phone)?
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Is the same port acting as both client and server?
i find something strange in this netstat output. the output is taken using netstat -a -n -o -p TCP command on win 7.
Proto Local Address Foreign Address State PID
TCP ...
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What changes to my network settings in Windows 7 can I make to achieve lower latency for gaming?
What changes to my network settings in Windows 7 can I make to achieve lower latency for gaming? I have heard of changing TCP settings in the registry, but I have also heard conflicting information on ...
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connect to a serial device via TCP socket
My setup is this:
serial device ttyUSB0 connected to laptop A
software that opens TCP socket to listen and write to, also runs on laptop A (linux)
My goal is to pipe data from/to serial device ...
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what is type of ICMP packets? TCP or UDP
The ping packet is a type of ICMP packet. Is there any relation between ICMP with TCP? In other words, can we guarantee their arrival in the network?
I want to know if ICMP packets in the network are ...
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Is there a way to pause/resume particular TCP connection?
I'm playing online game that matches me against random players. I found out that when I unplug my Ethernet cable, I have a minute to decide do I want this match to count.
If things go wrong, I just ...
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How to monitor TCP and UDP port changes
I am running software on a server that may be turning off some ports and need to find out what it is. I have the ports I need to check. I just need to find out what is turning them off. How can I ...
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How to prove provider is blocking incoming traffic on some ports?
I hope this is not too much focused on home networks, because that's where I hit the problem, but I think it may be of general interest nonetheless.
I have a cable connection (Cisco EPC3208) and a ...
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Can't connect to SSH server using WAN IP address [duplicate]
I have an SSH server behind a NAT router. Machines on the same (NAT'd) network as the SSH server can only connect to the SSH server using the LAN IP, not the WAN IP. Why?
My network looks like this:
...
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Program running from a folder where a parent folder is not accessible wont be able to use tcp layer
This issue is one that has taken me and our IT department at our company many hours to pinpoint.
The problem only appears on Windows server 2008, windows 7 and windows 8. On Windows XP or Windows ...
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Using tcpdump on displayed TCP data
If
sudo tcpdump -i eth0 -X
gives me
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
16:16:11....
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Ubuntu openVPN TCP no internet, UDP works. Win7 works on both TCP/UDP with same settings
I've recently purchased a VPN service which I'm connecting to with openVPN.
On Windows 7 I can connect on both UDP and TCP settings, but when I'm trying the same thing on Ubuntu 13.04, it gives me ...
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Using and testing UDP data over the internet [duplicate]
I have a GSM modem that sends data via UDP (it appears) I have configured it to send all data to my public IP address over the internet but no data is arriving at my end so I need to troubleshoot.
I ...
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Are all internet file downloads using FTP protocol?
I heard, FTP is used to transfer files over a network. Also heard that it uses TCP port 20 and 21. So TCP is connection oriented. We have acknowledgments. If the transmission is lost, we should be ...
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Filter outgoing connections but allow incoming
I a computer on my local network that I want to have accessible from any computer on the local network as well as from the internet, but I don't want it to be able to connect to other computers. I ...
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Monitor Application Network Activity
I use TCPlogView to see all tcp activity of a software.
for example:
An app (sample.exe) downloads this file in background: google.com/dl/sample.txt
when I track it with a TCP software I see this:
...
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How can I fire many HTTP requests using a single TCP connection?
I would like to know if there is a way to open a single TCP connection to a server and request several pages over HTTP on that connection.
Is there a way to do this using common Linux client tools?
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have tcpdump show the 'conversation' as i would get from wireshark?
Is it possible to get the same output i would get from:
tcpdump port 80 -w log.pcap
wireshark log.pcap
in wireshark Analyze > Follow TCP Stream and then in the bottom drop down Entire ...
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Load TCP New Reno protocol
I am doing some test of the congestion control protocols and I cannot find how to load the protocol New Reno. I loaded a lot of protocols like Reno, Vegas, Hybla, Bic, Cubic, etc using the sysctl ...
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Why is it possible to continue working in a ssh session after a network disruption?
What enables the Secure Shell client and server to resume communication after one or several network interfaces in the communication path between them is shut down and re-appears some moments later? ...
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Wireshark - How do i filter the TCP[RST] packet?
I am looking for filter out the TCP[RST] packets on wireshark.
I have tried tcp.analysis.flag but it didn't help.
user2633903
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Firewall is blocking echo request on port 7 (TCP)
I have an app which needs to receive a message back from the server. With the firewall on, I do not get the message back. If I turn off the firewall I get the request back.
I have added some rules ...
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Is it possible to suspend a socket (SSH session, specifically) to switch network devices?
When resuming a tmux workspace on my laptop, I regularly have to decide between the wired and WiFi connection. Ethernet has very low latency, but forces me to reconnect any time the laptop is moved. ...
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How to monitor TCP connections over time
I have an application which is a windows service. It accesses a number of other services using TCP/IP. E.g. sql server databases, informix databases, mail servers, etc.
For instance it will also ...
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How does a proxy know where to forward the requests to?
When a proxy receives a connection how does the proxy know where to forward the request to?
For example in Java we can set a system property for proxy.
So we set the IP of the proxy and the request is ...
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Data corruption after upgrading broadband speed and modem/router
I'm using an ISP called Fibertel in Argentina, and I recently upgraded my connection to 30 down/3 up. With this change came a new modem+router: the Motorola SBG 6580.
Before I had something like 1 ...
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Network Traffic per process/application windows
I know that there are plenty of applications to do this (like procexplorer) but is there anyway to access the winapi (what method/reference is used) to retrieve the network traffic (TCP, UDP, etc) per ...
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