Netcat is a simple but powerful utility program that reads and writes data across network connections, using TCP or UDP protocol, IPv4 or IPv6, with a variety of functions.

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ssh -R then expose the local port over HTTP?

Here's my scenario, I have two machines, A and B. A is behind a VPN, so B can't get to A. I have a web server: machine_a$ curl localhost:8088 "hello from machine_a" I have executed a remote SSH ...
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1answer
67 views

Unable to transmit stream through OpenVPN tunnel

We are trying to transmit a video-stream via netcat from a OpenVPN server to a client. The server is a Raspberry Pi with Pidora running on it. The client is a Notebook with Ubuntu 12.04 and has a ...
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1answer
43 views

Is it possible to set up my own DNS for my computer?

I don't know if I ask the right question but I hope this situation would give you the whole picture. I have my PC which located at my apartment. As usual, I get access to Internet using service ...
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2answers
376 views

How to send a binary message in TCP and store the response

I have to develop a client for a proprietary protocol and it would be very useful to be able to understand the behaviour of the existing server by sending it custom messages and look at the answer. ...
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1answer
103 views

Knock on a port to get service and version

I'm having difficulty remmebering a certain command I would use in bash that would give information about a port it would 'knock' on. I've used ssh backdoors before so that I can access my home ...
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1answer
685 views

Can I use nc and/or stunnel to make a transparent SSL proxy such that I can specify the outgoing source port?

I've been playing around a bit with different variations and can't seem to find something that quite works. I want to be able to 'bridge' an SSL connection across a particular gateway node in the ...
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3answers
971 views

Using nc (netcat) to emulate NTP server response

I want to test some security on an NTP client developed in-house and would like to use netcat to do it. I have packets captured with Wireshark from previous NTP exchanges that I tried to feed to the ...
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1answer
491 views

How to purge connections left open by SSH ProxyCommand?

I have a webserver WWW1 and a front-facing proxy PRX. I use SSH ProxyCommand to connect to WWW1's internal IP (private IP) via PRX (private+public IP). For some connections (not all) I see a network ...
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nc or socat: How to read data from remote:/dev/ttyACM0?

I have a device running at a remote computer on /dev/ttyACM0 Now I want to read that data on my computer. I can connect to it over ssh. Unfortunately I am a nc/socat rookie and no howto covered this. ...
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73 views

Why is Udcast is many times faster than Netcat?

I use Netcat once in a while to copy files or disk images over the network. While it does the job I always felt like it was always on the slow sluggy side regardless of using ssh, no ssh, compression ...
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1answer
75 views

Netcat: Should I use Ctrl+C to close the connection?

I've opened netcat, and I'm entering things from the keyboard. When I've finished and I want to close the connection, should I just hit "Ctrl+C"? I want the connection to be closed "normally", but I ...
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112 views

pipe a serial port to a command that blocks? </dev/ttyACM0 nc -l 1234

For practical purposes I have only one shot at testing this, so I wonder how will </dev/ttyACM0 nc -k -l 1234 work when no client is connected. Will the kernel buffer all the serial data, will the ...
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75 views

netcat command is not working in bidirectional mode

I am using netcat in Linux to send and receive data (using udp protocol) from a serial port to another device through the network. The command is : nc -u 192.168.10.12 < /dev/ttyUSB0 > ...
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1answer
108 views

Keep Process Running after Quitting NetCat

I am using NetCat on Windows 7 Professional to connect to my linux machine at home. I need to run a process and make it keep running after I close NetCat (Cmd Console). However when I close and then ...
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0answers
146 views

Netcat one-time message

I'm trying to use Netcat to debug a UDP listen server that I'm writing, and I'm surprised by the behaviour: $ echo -n Hello World | nc -v -u -6 localhost 12201 - Connection to localhost 12201 port ...
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121 views

Forwarding traffic using nc on a linux box

On my system, I am sharing my internet which is on eth0 (ethernet) through wlan0 (wifi card). I am then using mitmproxy to monitor the traffic and look into the ssl packets. However, mitmproxy only ...
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2answers
168 views

Is it possible to push video out and usb over TCP/IP

I have a security camera system that is running Linux and is placed near the cameras (not in an office). It has a VGA out and uses a USB mouse. I'd love to redirect the VGA and USB to another ...
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2answers
302 views

List incoming connections on nc (netcat)

I set up nc on some computers in my office. They're connecting to our server like so: nc 192.168.1.2 3291 -e cmd Does anyone know how to list incoming connection attempts rather than accept one? ...
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578 views

Server: Microsoft-HTTPAPI/2.0 running on port 10234 on my Windows 7 pc?

I've recently set up a home server and spent some time working on the security. One of the tools I've been using nmap which I pointed at my Windows 7 desktop. It showed an unknown service on port ...
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1answer
373 views

TCP connection to my host's public IP address using Linux netcat

I need to make a TCP connection to my machine through an application that needs only the public IP address and port to connect. I have been able to do it in Windows, but I need to do it in Linux ...
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2answers
498 views

How do I send and receive simultaneously with netcat?

I need to test a TCP server by connecting with netcat as a client sending a stream from /dev/random and at the same time pipe the output to /dev/null. Receiving: nc 127.0.0.1 3000 > /dev/null ...
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3answers
774 views

How do I make netcat receive UDP packets from any host?

Is there a way to make netcat receive UDP packets from any ip:port? I don't want it to bind to a specific host as the first packet comes. I can consider alternatives, but they have to be bash ...
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1answer
801 views

netcat and tee redirection via a bash script

Quick question that has been haunting me all day.. I have a bash script that includes this line: nc -l 8044 | tee nc-output & The output from netcat is never being written to nc-output. If I ...
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0answers
1k views

Port forwarding on D-link DIR-615 router

I'm attempting to configure my router to forward a port to my Linux machine. The Linux computer has a static IP (192.168.0.185) Right now I'm just experimenting to make sure I can forward a port, so ...
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1answer
249 views

cat file that contains escaped characters to netcat

I'm trying to test a webserver with some HTTP request written in a file. GET / HTTP/1.1\r\n\r\n Right now I'm feeding that file to netcat like this: cat files | nc localhost 80 However, the \r\n ...
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Meaning of “netcat can be used as a backdoor” [closed]

I recently read about netcat and it is often mentioned that it could be used as a "backdoor". What exactly is meant by backdoor? Could some one give an example of such usage of netcat.