Netcat is a featured networking utility which reads and writes data across network connections, using the TCP/IP protocol.

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5answers
20k views

Netcat (nc) traditional package for RHEL 6.x?

I'm trying to use the Percona Apache Monitoring [Cacti] Template for Memcached. They do indeed warn that you can't use the openbsd version of the package and provide a solution for Ubuntu/Debian ...
0
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2answers
117 views

Why my netcat connection doesn't send the file correctly?

I wrote this script to send a file using netcat. My intention is to open the netcat port in the destination server from the origin, this way I do everything with just one script instead of having one ...
2
votes
1answer
894 views

How to test nagios send_nsca with netcat

I am trying to write a unit test of send_nsca using nc but it is failing. I want to start nc to listen to the nsca port and then use send_ncsa to send a message to that port. In one terminal I am ...
1
vote
1answer
33 views

make netcat listen for multiple UDP packets

If I run a simple UDP listener like this: nc -l -u -p 1234 Then I appear to only get the first inbound UDP packet. For example if I run: $ echo abc | nc -u localhost 1234 ["abc" appears in ...
1
vote
1answer
138 views

tcp retransmit via curl and netcat

I'm trying to setup iptables to cause realistic network failures between docker containers. On the server, I run both netcat -lk 1234 and an Erlang cowboy server. On the client I run clients: echo ...
1
vote
1answer
321 views

netcat doesn't transfer complete file when using UDP

I use the following in order to transfer bigfile (11GB): cat bigfile | pv -L 11m | nc -u 10.0.0.1 3333 After 1.6GB the client stop to transfer (in the target machine i dont see packets ) This is ...
0
votes
1answer
22 views

Proxy to add CORS headers with netcat

I'm looking for a little script using nc which will be used to add CORS headers (at least Access-Control-Allow-Origin: *) in order for my local ionic dev application to access a remote webservice.
0
votes
1answer
35 views

Netcat - socket in time_wait when echoing and piping, but not when invoked directly

I'm testing an application using netcat (nc) and I'm getting very low throughput on network connections. When I ran netstat -tnpo I see numerous TCP sessions in TIME_WAIT. I'm sending data to my ...
0
votes
1answer
285 views

2012R2 Hyper-v host CentOS7 guest slow network speed over external network

I have a Hyper-V host on win2012R2 (Version 6.3.9600) with two gigabit network adapters, one of them connecting to a gigabit router (the another one is currently out of use because lack of a gigabit ...
0
votes
1answer
131 views

When copying VM filesystem over netcat, dd copies double the disk size

I'm attempting to copy the disk of a working headless virtualbox VM (VM1) on one server to a new VM (VM2) on a vCloud server. I don't have access to the host of VM2. The OS is Windows Server 2003 (32-...
0
votes
1answer
4k views

How to execute a reverse “Powershell shell” using ncat or netcat?

I am using ncat to execute a reverse "cmd" shell from one machine to another and without any issues using the commands: In my machine: ncat -l 443 In the remote machine: ncat <my ip> ...
0
votes
1answer
232 views

How to query a munin plugin via netcat?

I want to query a present Munin plugin from Nagios. As I would like to do some calculations and aggregations (the plugin reports data over a period of time) and not just look at the last values, the ...
0
votes
1answer
136 views

Netcat: connection lost before transfer is complete

Interesting thing with Netcat (nc) in CentOS 5 or 6 (nc-1.84-10.fc6 or nc-1.84-22.el6.x86_64). How can I work it around? I can't find a bug about this, but It models a file transfer to a remote host,...
-1
votes
1answer
32 views

Can't connect to socket from outside

I have a problem on my server when I start an application that listen to a port: I can connect to it from the same machine, but not from the ouside world. I noticed this problem when trying to create ...
2
votes
0answers
237 views

Postfix mailbox_command + netcat + nodejs

I use Node.js script to process incoming emails and pipe them from Postfix via netcat in mailbox_command (namely: nc 127.0.0.1 3002). Node is listening on port 3002 and calls socket.destroy() once ...
1
vote
0answers
76 views

Investigating connectivity issue

I'm trying to set a up a new service on a server that is running apache, however it seems like incoming traffic on that specific port is blocked, although I do not understand why. On the first server, ...
0
votes
0answers
54 views

How to make a tunnel connection behind NAT with iptunnel/netcat?

How can I create an IP tunnel to a server on the internet with a device that is firewalled behind a NAT? I need to do this using only the commands iptunnel or nc. I'm not controlling the NAT router. ...
0
votes
0answers
52 views

multiplexing a TCP connection through a dumb shell connection?

I am connecting to a VPN whose gateway is sufficiently misconfigured that basically the only useful thing I can do with it is to ssh to a specific Linux host set up for my usage inside the VPN, and ...
0
votes
0answers
7 views

Banner Grabing - Neccessary steps involved?

I want to check if it is necessary to enumerator all the banner in any given server. Using my following instance. And also to check if I miss out anything like using HEAD instead. Would like a better ...
0
votes
0answers
51 views

nc exits immediately, on connection, when run as an upstart job

I'm using the following /etc/init/jsonlog.conf upstart job: description "jsonlog" start on runlevel [23] stop on runlevel [06] respawn script cd /tmp echo "about to listen" /bin/nc -l ...
0
votes
0answers
38 views

netcat UDP port test response issue

I am running a game server on a Windows Server 2008 VPS/VDS through port 12203. I want to be able to automatically restart the game server exe file if it crashes. So, my strategy is to use netcat to ...
0
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0answers
19 views

netcat relay mirror for arbitrary protocol number

How can I set up netcat to listen for incoming packets on protocol number 150 and send them back (to the source IP of the packet) with the same protocol number? So, everything that arrives on the host ...
0
votes
0answers
183 views

Remote backup with netcat and Ansible

I try to backup my servers with Ansible. My setup is like this: SERVER 1..n (my data I want to backup) ANSIBLE_HOST (on this server my Ansible backup playbook is executed by a cron job) ...
0
votes
0answers
152 views

network throughput test: iperf vs netcat

I'm trying to measure the throughput of a 10 Gbit/s network. With iperf test I'm reaching about 9,3 gbits/s. However when I'm trying to copy some data with netcat, I'm getting just about 1,8 gbits/s. ...
0
votes
0answers
129 views

netcat not listening on desired port

When I want to listen on desired port on one server, I use netcat ie: nc -l 8888 Then I can verify the server is actually listening on that port: netstat -tlnp | grep 8888 tcp 0 0 0.0....
0
votes
0answers
345 views

Piping device file over UDP with netcat

Hopefully this is the best Stack Exchange site for this - I think it's primarily a netcat question. I'm developing a custom data acquisition device. It can probably be best thought of as a fancy ...
0
votes
0answers
668 views

Send apache ssl access log to syslog

I'm having an issue piping apache ssl access logs to my syslog server. I've added the following line to my apache config: CustomLog "|/usr/bin/nc -u <syslogserver> 514" "<134>%{%b %d %X}...