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send echo to socket network

Terminal - send echo to socket network
echo foo | netcat 25
2009-09-13 01:33:02
User: pykler
Functions: echo
send echo to socket network

Using netcat, usuallly installed on debian/ubuntu.

Also to test against a sample server the following two commands may help

echo got milk? | netcat -l -p 25

python -c "import SocketServer; SocketServer.BaseRequestHandler.handle = lambda self: self.request.send('got milk?\n'); SocketServer.TCPServer(('', 25), SocketServer.BaseRequestHandler).serve_forever()"


There are 2 alternatives - vote for the best!

Terminal - Alternatives
echo "foo" > /dev/tcp/
2009-09-12 16:48:05
User: mobidyc
Functions: echo

this command will send a message to the socket 25 on host in tcp.

works on udp and icmp

understand only IP address, not hostname.

on the other side (, you can listen to this socket and test if you receive the message.

easy to diagnose a firewall problem or not.

echo foo | ncat [ip address] [port]
2012-10-26 10:53:47
User: dragonauta
Functions: echo

you can use a pair of commands to test firewalls.

1st launch this command at destination machine

ncat -l [-u] [port] | cat

then use this command at source machine to test remote port

echo foo | ncat [-u] [ip address] [port]

First command will listen at specified port.

It will listen TCP. If you use -u option will listen UDP.

Second command will send "foo" through ncat and will reach defined IP and port.

Know a better way?

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