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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Netcat connection closes after connecting through python

So I have installed Netcat on my raspberry pi and my mac and I can get them to connect really easily. Problem is that if I want a python script on my mac to establish the connection when the raspberry ...
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2answers
38 views

How do I interactively type \r\n-terminated query in netcat?

$ nc example.com 80 GET / HTTP/1.1 Host: example.com HTTP/1.1 200 OK ... It works, line separator is just 0A here instead of required 0D0A. How do I type a 0D0A-separated query in netcat? It is ...
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1answer
26 views

How to store data from different netcat connections in separate files?

I need a server that should receive data streams, store them in files and send further. Each connection should create a file with corresponding timestamp in file name, then write to it. My solution: ...
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25 views

nc and named pipes for port forwarding

I have my environment setup to listen to jetty on port 8888. However, for a limited time, I will have to also listen on 8889. I though of using named pipes and nc for that: mkinfo pipe1 /bin/nc -l ...
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1answer
53 views

How do I make netcat timeout nonsilently?

I'm trying to send some data to a server with a command like nc -w 3 IP_ADDRESS PORT < data where nc is the netcat from FreeBSD 5.4. When the server doesn't respond within 3 seconds I get no ...
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1answer
35 views

How to netcat all the files in my directory?

I have a directory of files I'd like to netcat to another machine. For one, I use nc <ip> <port> < sample.fls But if I have a directory of sample1.fls sample2.fls sample3.fls ...
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35 views

netcat between mac and linux only working in one direction

I have two machines on the same local network. One is a Mac (192.168.42.74) and one is a Dell (192.168.42.75) running Kubuntu Linux. If I issue 'nc -l 12345' on the Mac and issue 'echo "blah" | nc ...
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2answers
70 views

How to keep the reverse shell open in Netcat?

As soon as the command prompt is closed on the target machine the reverse shell is closed on the client machine. Is there any way to keep the port open and Netcat working after the target machine ...
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1answer
126 views

how to make a batch file close automatically

I have a .bat file which its content is like this: @echo off nc x.x.x.x 23 < commands.txt exit in which nc is a .exe file in the same directory nc.exe known as NetCat. The commands.txt file ...
2
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1answer
72 views

Probing a port for RDP

I use an ssh tunnel to RDP into my home computer ("home"). Occasionally, the tunneling software running on home crashes and the RDP port stops getting tunneled. I've attempted to resolve this by ...
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63 views

Creating a proxy with netcat

I'm trying to setup a permanent proxy server for one of my servers to reroute connections having issues. The proxy server is running Centos 7 x86 User -UDP or TCP-> Proxy -> Server I am am ...
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1answer
108 views

automatically start netcat on localhost and remote-host and keep it active

I found this answer by @jeremytrimble on Stack Overflow which explains how you can read a FIFO file over network. I wonder if it’s possible to start these netcat commands automatically, e.g. in a ...
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1answer
69 views

Bash - Parsing XML output of nmap

I am trying to write a bash script that will take port id I retrieve from an nmap command, and then use those ports to send a file using netcat. So I got some basic knowledge using this link, How can ...
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0answers
46 views

Give a command HTTP proxy auth access

I'd like to let a command (wsimport) access a URL through an HTTP proxy with authentication. It can be configured to use a proxy, but not with auth. I was wondering if a tool such as netcat, or any ...
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0answers
46 views

How to connect two debian VMs using vmware workstation so that one acts as a web server and the other as web client

I want to connect two virtual machines running using VMWare workstations - Debian Linux and I have setup private DNS server on one VM named "Server" and other VM is named "client". I am trying to ...
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0answers
26 views

How to send OUTGOING to 1 netcat connection whilst reading INCOMING in a while loop?

I'm currently using netcat to grab the incoming lines of data with following: nc 192.168.1.1 1234 | while read line; do echo $line done I need to send outgoing data to the same connection, ...
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1answer
21 views

OS X LoginHook - nc exits prematurely for no apparent reason

I'm trying to use loginhook to download large amounts of data and I've been having problems which I've nailed down to nc exiting prematurely for no apparent reason. This is a simplified test script: ...
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0answers
55 views

SImple server to run program and return result

I am attempting to create a minimal local listen server that takes an input request, pipes the input to a program and then returns the result of the command. What I have at the moment is the program ...
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55 views

Port bridge with iptables

is there a way to achieve the same thing than bidirectional socat functionality with nc mkfifo backpipe nc localhost 42042 0<backpipe | nc localhost 1042 1>backpipe But only by using iptables ...
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1answer
30 views

Using netcat to connect to znc

I'm trying to send status updates to my IRC channel on irc.foo.com My limitations are.. The msg has to be sent to irc.foo.com from my ZNC account on znc.bar.com (znc is connected to irc.foo.com) ...
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46 views

Netcat doesn't detect open port with ngrok

I'm using ngrok 5002 to open up a port on my computer. I then do netcat -z xxx.xxx.xx.xxx 1-65000 with xxx.xxx.xx.xxx being my external ip I found via some web service. However, I expected ...
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108 views

Netcat redirect remote console application

I have a windows interactive command line application ('pianobar', Pandora client) that I'm running on a Win2k8 server that I would like to control remotely, possibly using netcat. I need to be able ...
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16 views

Using DJB's tcpclient or tcpcat bidirectionally

Can someone post an example on how to use DJB's tcpclient bidirectionally? We need to read from Tor's ControlPort as well as write to Tor's ControlPort. A "file" that is open for both, reading and ...
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1answer
366 views

Multiple unix pipes not working

This first pipeline works fine (printing "c"): echo "a" | sed 's/a/b/' | sed 's/b/c/' This one does not do what I expect (nothing gets printed when I feed an "a" into my fifo ): mkfifo fifo; cat ...
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2k views

Netcat error: Can't grab 0.0.0.0:80 with bind

When I tried to listen on port 80 in Windows 7 with netcat, I get this error: C:\Users\sashoalm>echo "hello, world" | netcat.exe -l -p 80 Can't grab 0.0.0.0:80 with bind On the other hand, ...
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1answer
56 views

Quickest way to upload to a server?

I am looking for a way to upload a large file (1gb) to a server. So far I have used scp, nc and sftp. Initially I start with a nice upload speed of around 2 mbps, but this quickly slows down to around ...
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1answer
342 views

How to send message both to netcat and other script?

I'm trying to make some client-server interface. Think of it as one-on-one chat. What I want to achieve are two horizontal views. Bottom for my (server) input, top for client output and my input. ...
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97 views

DNS tunneling through an SSH connection looses connectivity

In the article 'UDP traffic through SSH tunnel', it is described how to tunnel DNS trough a SSH tunnel: client# ssh -N -L 6667:localhost:6667 user@server server# mkfifo /tmp/fifo server# nc -k -l ...
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1answer
680 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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3answers
250 views

Quick way to scan for opened ports on local network according to a list

How can I quickly find out whether port 80 is open/listening on a server via a bash script? Normally on all workstations the daemon is running, but sometimes it fails. I use the following command to ...
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1answer
4k views

Listen to port continuously and dump data to file

I use this command to listen to port and dump data to file: while : ; do nc -l 0.0.0.0 10000 > log.txt & done First request works perfect, it's dumped in log.txt but after first request, ...
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1answer
510 views

Saving Live Video received through Netcat

I'm using the following command to stream a video which I receive through Netcat. nc -l -p 5001 | mplayer -fps 31 -cache 1024 - (On Windows CMD) This command opens the MPlayer and plays the live ...
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7answers
3k views

How can I verify that a 1TB file transferred correctly?

I frequently transfer VM images from hypervisors to an archive server for long term storage. I transfer using netcat since it is faster than scp, rsync, ect.. hypervisor$ cat foo.box | nc ...
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1answer
1k views

How to wait for a response on the inbound side of the socket using NC command under BusyBox?

I am having problems using the Netcat that comes with BusyBox 1.1.3 to make an HTTP request and then receive the response. The NC command seems to quit out as soon as it reaches the end of the request ...
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1answer
388 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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2answers
2k views

Why is the '-e' option missing from netcat-openbsd?

Why is the -e option missing from the netcat-openbsd package? There is a netcat-traditional package but it has many features from the OpenBSD package missing. I am running Linux Mint 16. Does anyone ...
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0answers
156 views

Create duplex TCP tunnel in Windows with netcat

I need to create a TCP tunnel in Windows, I tried by chaining netcat: ncat -l 3333 | ncat 192.168.0.110 4015 This creates a single direction tunnel, though, as only the first netcat's STDOUT ...
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1answer
296 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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233 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 > ...
0
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1answer
57 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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0answers
218 views

nc connection refused even on loopback

I'm working on an embedded linux system, which appears to be networked correctly and is running ssh (dropbear) and rpcbind. I'm setting up a server application on it, and every single thing I try ...
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1answer
292 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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1answer
505 views

X11Forwarding using SSH and Netcat

From my machine, I must connect through nodes A, B, and C, to reach target: localhost -> A -> B -> C -> target Machine A is configured to refuse X11 Forwarding, so I guess I shouldn't ...
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2answers
692 views

Why can't nc / netcat sniff http port traffic easily?

I'm NOT looking for advice such as "try wireshark." I'm trying to understand what netcat is and isn't. When I try to listen (-l) to port 80, it says "address already in use." Can netcat not listen to ...
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1answer
87 views

DDNS and NetCat

I'm messing around with netcat(windows) and i'm trying to configure netcat listening to external connections.My ISP provides me dynamic IP so i gotta find a way to have netcat connecting back to me no ...
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1answer
168 views

Netcat connection over dynamic IP

I was playing around with netcat on my lan , had PC1 configured as a netcat client and PC2 configured as a netcat server into a reverse netcat TCP connection.This whole reverse TCP connection works ...
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1answer
8k views

Can I pipe/redirect a console application through netcat so it can be used remotely?

Is it possible to 'pipe' an instance of a console application through netcat, so netcat is listening for a new connection and redirects the stdin and stdout over the network connection.
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2answers
1k 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
440 views

netcat output into separate files using string delimiters

I want netcat to pipe the output of a tcp/ip connection to commands that examine the output and split it into distinct files separated by the strings "msg" and "/msg" from the output, something like ...
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3answers
374 views

Use xargs to send requests to the same server in parallel with netcat

I am trying to devise a one-liner to send text to a simple echo server - but multiple connections in parallel. This is what I'm trying: echo -e A,B,C,D | xargs -d, -i -P 4 echo {} | nc localhost ...