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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ppp(d) configuration options: Does "noccp" also disable vj compression?
I'm having trouble understanding the docs for pppd. The Oracle man page states that disabling CCP (using noccp) disables deflate and bsdcomp - both of which are data section compression.
However, it ...
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Why do we need L7 reverse proxy for increasing the limit of max TCP connection to the backend?
I stumbled upon a YT video- 5 mins which explains that there's technically no limit to the number of connections that can be opened between the clients and servers even if there's a reverse proxy ...
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Windows8 drops network connection shortly after boot (but works if I wait)
I have a test lab which runs tests against Windows8 machine, more specifically a Pytest project which generates TCP traffic from my Ubuntu machine to Windows8 machine, and from the Windows8 machine ...
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How to force `telnet` (in TCP mode) to send bytes immediately?
In Linux, when I run telnet <address> <port> and then type things, it buffers data and only sends collected line when I hit Enter. Furthermore, it buffers up to 4096 characters and ...
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File service latency is high, How to troubleshoot?
This service is a file upload service and the request packet capture in the live network is as follows:
The data uploaded by the client is halfway through, and then it will not be sent
The server ...
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How to send back TCP packets using iptables
I am trying to demonstrate TCP communication with a Ubuntu 18.04 box (which mocks a QNX setup) that does not have a listener installed. Consider that due to some license issues it might not be ...
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Trying to stream a video loop using FFMPEG. However, I keep getting the error "Cannot Write the Headers Server returned 400 Bad Request"
I am using mediamtx for starting RTSP server. The command that I am using for ffmpeg is as follows:
ffmpeg -re -stream_loop -1 -i ./clouds.mp4 -f rtsp -rtsp_transport tcp rtsp://localhost:8554
The ...
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Termux ssh connection over usb-c result in connection closed by remote host
I got an Oneplus 8 with Kali NetHunter.
I want to ssh to Termux and I can, but only if the device connect to my LAN at least once.
If I restart the phone and I jump the connection with WiFi/internet ...
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What prevents unsolicited internet packets from using up my monthly data limit?
My home router can use port-forwarding to act as a server, so I assume all internet packets
sent with my public IP address as a destination are hitting it (and just not getting any
response from my ...
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Download so many tiny files without archiving? [closed]
I want to implement a file server for a mobile app. This app requires so many tiny files to be downloaded from the server before it begins it's work And with updates from version to version some files ...
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Is it normal to get no retransmissions using TCP on Nordic Boards?
For a Projekt I am connecting 2 Nordic Boards together over IEEE 802.15.4 and measure their bandwidth using TCP. The two nrf52840dk Boards are 1m apart (one acting as a border router for my PC).
...
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What is stored in the "Winsock Catalog"?
Another user's question prompted me to write this one.
I have no purpose for the question other than curiosity.
Does anyone actually KNOW what is stored in what is called the Winsock Catalog? At the ...
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Low Windows bandwidth in google cloud platform
I have an on-premise site with mainly Windows resources and an up-to-date Forti firewall as the central communication device. This site is connected through a partner interconnect created according to ...
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socat TCP server bidirectional using sleep, non-interactive client returns without response. Server reports: I/O error
I have the following TCP server:
socat TCP-LISTEN:10000,fork,reuseaddr SYSTEM:'read -r msg && sleep 3 && echo "OK"'
When I execute (interactive mode):
socat - TCP:localhost:...
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TCP Retransmission (TCP Port numbers reused) issues
I developed a web server and this is running on GKE.
Whenever I send any request to this server from my local pc, it occurs TCP retransmission.
Following is captured packets with Wireshark. The red ...
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What cause client not to sent [ChangeCipherSpec] package
I face a problem. i have a device when doing TLS handshake, Client fail to send [ChangeCipherSpec], currently all https website is failed but http is working.
i check it from wireshark, it show as ...
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Why does my LAN NIC get a lot of TCP retransmissions and timeouts?
yesterday I recognized that git cloneing repositories from my private GitLab instance wasn't working consistently. My internet connection is fine and I can also visit GitLab's web interface without ...
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tls wrapper over plaintext tcp
is there any tool I can make tls forwarder over raw tcp?
I have a server which has no encryptions, purely plaintext tcp comunications.
I wanna connect to it over tls but cannot change the server code.
...
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TCP to virtual serial port with socat
I have a program (program 1) that has a TCP server listening on port 1234. I have confirmed that the server accepts connections and sends data with a utility str2str.
Program 2, on the same machine, ...
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How can I get connection attempts behind a NAT router?
I've been playing with nftables recently and set up logging every incoming TCP SYN packet to my local machine. I noticed every minute I get a couple of random connection attempts on various ports (...
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Python TCP socket connection between Linux and Windows10 not working as expected
I am trying to establish a TCP connection and sending packets over a python socket server-client. I am using Windows 10 as my main system and VM Kali-Linux on the other side
I used Windows as a client ...
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How to run a program as administrator
Is this a joke?
Nothing as simple as running a program as administrator: click-right on the name of the program in Windows explorer, choose "Run as administrator" from the context menu and ...
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Is it possible to force TCP to find another path to the host?
I have two operating systems on my computer, in one TCP normally finds the path to the host, and in the other traceroute breaks off halfway. Is it possible that the route is somehow cached? If so, is ...
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ICMP packet with TCP?
For some time now I have found myself interested in packet analyzing and I try to figure out all kinds of stuff that I see in network captures. I hope you guys might want to help me find out this one.
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Possible to use shell script that does loopback to localhost when receiving a packet?
I want to run a shell script, that sends a packet to localhost (loopback) when it receives a packet from anywhere.
I am using netcat.
nc -lp $port, and then echo test | nc localhost $port works.
But, ...
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Port Forwarding not working on cellular data but working on wifi
I recently developed a web app using Express and Node.js and I am hosting it locally on my PC. I set up my router to port forward HTTP requests to the web app to my PC. It works fine whenever the ...
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ModuleNotFoundError: No module named 'pyModbusTCP'
I am trying to run a python file on bootup which will collect some data from another device.
I created a service in the /etc/systemd/system directory
[Unit]
Description = File which requests data from ...
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How to measure the latency to a webserver?
I wish to measure the TCP network latency from my Linux server, to a websocket URL.
I am using netperf like this:
netperf -H ws.the_websocket_url.com -l 5 -t TCP_STREAM -v 2 -- -o min_latency,...
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What does Firefox's PR_CONNECT_RESET_ERROR mean?
When I browse to https://unesco.org from Firefox, I get the error PR_CONNECT_RESET_ERROR. But https://www.unesco.org works.
I couldn't find Firefox's documentation on this error despite several Google ...
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Shadowsocks doesn't work.ICMP is working but TCP does not
I installed Shadowsocks on a Google cloud server (Debian 5.10.149-2) and ShadowsocksX-NG on Mac.
But it doesn't change my IP address.
If I chose Global mode, no website couldn't be accessed.
What I ...
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TCP Vs UDP for VPN
What is the best protocol between UDP and TCPU for a VPN ?
Many VPN providers are using UDP because of the speed gain, but what if it's used to connect to an Infrastructure to access Databases or ...
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Trying to secure my home network. Is it normal to have this many open TCP ports on my devices?
I recently bought Debokee (aka LANscan) & LittleSnitch. I'm wondering if this scan looks strange to anybody? I have a strong suspicion with evidence that my network has been compromised. I am just ...
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How can the same TCP port show in netstat as BOUND and ESTABLISHED in Windows?
I'm investigating an issue of port exhaustion in Windows, and the output of netstat shows many ports both as BOUND and ESTABLISHED
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TCP 10.0.1.9:64318 10.0.1.9:8400 ESTABLISHED ...
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TCP transparent proxy with cgroups2: How can I allow TCP traffic only and block all the rest coming from a cgroup?
I'm trying to setup a TCP transparent proxy with cgroups2:
iptables -t nat -A OUTPUT -p tcp -m cgroup --path test --syn -j DNAT --to-destination 10.0.0.1:10000
iptables -A INPUT -p tcp -m cgroup --...
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OpenVpn doesn't connect via TCP
I created a OpenVpn server with TCP but client can't connect and receive this error
Server poll timeout, trying next remote entry...
But UDP works perfectly.
This is config of server:
local a.b.c.d
...
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Connecting to a home server on a cellular hotspot
I am seeking advice on a networking issue I have run into recently. I suspect that I a making an obvious mistake in my assumptions about connections between machines on separate networks.
My goal is ...
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How to access to a SQL Server Instance from a WSL2 Debian System?
I would like to connect from my WSL 2 Debian System to a SQL Server instance. This is because I want to develop an cossplatform app in Python and make some tests.
WSL 1
As far as I know with WSL 1 I ...
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New LAN from Linux PC
I've got one Linux PC connected to the Internet but I want to connect more devices to the PC using TCP/IP but I don't want the router to act as a DHCP Server for them. I mean, I don't want the router ...
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iperf3 fast in first second
i have a question to my iperf3 results.
the connection i through a wireguard connection where the server is location in DE and the Client located in IL.
Tests have been conducted from the server (DE)
...
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Why does my virtual machine (Debian on Proxmox) not respond to a TCP SYN of another VM even though it arrives?
I got a very strange problem and I am out of ideas to solve it. I hope anyone over here has a helpful idea.
Some info about the virtual machines:
VM0: Debian 10 - 192.168.10.102 [+ 2 more interfaces]
...
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Is there anything preventing modifying linux's tcp stack to have over 65,535 ports?
I was reading this and started to wonder of there was anything preventing me from just modifying a copy of the linux tcp stack to support more than a 16-bit header to allow for more ports. Would this ...
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How do I stop TCP reset packets?
Full story: This has been quite the odyssee, finding out who is sending these TCP reset packets. The isp pointed me in the direction of the minecraft server, the minecraft server said it has to be the ...
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How to have Windows firewall send RST packet for blocked port
Is there any way to instruct windows firewall to send Reset packets for a blocked TCP connection instead of dropping the packet?
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Strange limitation on single TCP/UDP connection with bandwidth limitation
I have a weird behaviour with connections from my house in Israel to my VPS or dedicated server in the EU.
A single connection TCP/UDP is somehow limited to around 400kbps for some reason. When using ...
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Force windows to communicate to specific ip addresses via specific network card
Hello I'm currently facing issues with tcp communication on a windows 10 system with two network cards.
I need to connect specific hardware which is in a LAN.
Sometimes windows uses the network ...
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What is the correct way of shorten this nat based multiple ports?
Can these rules shorten to single line:
post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 3050 -j DNAT --to-destination 192.168.1.3:3050
post-up iptables -t nat -A PREROUTING -i vmbr0 -p ...
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What is the source ip dest ip source mac and dest mac in Gratuitous ARP response
So I am sitting at host A. And I need to send Gratuitous ARP response to Host B. in Gratuitous ARP response I dont know the mac address of Host B my computer on LAN. But can I add 0xFFFFFFFFFFFF to my ...
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Finding Public Ip Address of security camera
I have installed my home security camera and it's run on 192.168.192.2 localhost and is accessible through android apps. But I would like to know what the public IP address of this camera is so I can ...
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Outgoing TCP traffic redirection
I have a program that attempts to communicate with an old server on the 1.1.1.1:5555 (for instance) using TCP. The problem is that I no longer have access to that IP (my new server works on 2.2.2.2:...
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Open shells with ncat on wan target
I created an azure VM and I configured a ngrok server to make my localhost accessible from internet and I put a VPN to VM in order to simulate a wan attack.
What I want is to set a TCP connection to ...
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