Commands tagged udp sorted by votes

Commands tagged udp (6)

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send echo to socket network

this command will send a message to the socket 25 on host 192.168.1.2 in tcp. works on udp and icmp understand only IP address, not hostname. on the other side (192.168.1.2), you can listen to this socket and test if you receive the message. easy to diagnose a firewall problem or not.
This is sample output - yours may be different.
25

echo "foo" > /dev/tcp/192.168.1.2/25

mobidyc · 2009-09-12 16:48:05 31
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(('0.0.0.0', 25), SocketServer.BaseRequestHandler).serve_forever()" Show Sample Output
This is sample output - yours may be different.
```
got milk?
```
2

echo foo | netcat 192.168.1.2 25

pykler · 2009-09-13 01:33:02 4
send raw data (hex written)using UDP to an IP and port

Use it to send raw data to a networked device. Used to interact with relay controller board whose documentation is lost, so use wireshark to sniff the sent data and replayed using the command.
This is sample output - yours may be different.
1

echo -n 023135 | perl -pe 's/([0-9a-f]{2})/chr hex $1/gie' | nc -4u -q1 -p5001 192.168.0.100 2000

sucotronic · 2013-09-18 14:31:47 8
Display any udp/tcp connections by process name or by process id

Where COMMAND is the process(es) name. I prefer to get all states but you may add ESTABLISHED in the grep regex. lsof -c apache2 | egrep -o 'TCP.*ESTABLISHED.*$' -nP flags are optional and UDP is irrelevant for established connections Similar but using the process id: lsof -nP -p PID | egrep -o '(TCP|UDP).*$' Show Sample Output
This is sample output - yours may be different.
```
$ lsof -nP -c apache2 | egrep -o 'TCP.*$' | sort -u
TCP 192.168.0.2:443->192.168.0.136:3373 (ESTABLISHED)
TCP 192.168.0.2:443->192.168.0.137:11127 (ESTABLISHED)
TCP 192.168.0.2:443->192.168.0.137:11153 (ESTABLISHED)
TCP *:443 (LISTEN)
TCP *:80 (LISTEN)

$ lsof -p 17279|egrep -o '(TCP|UDP).*$'
TCP 127.0.0.1:32434 (LISTEN)
UDP *:32435 
```
0

lsof -nP -c COMMAND | egrep -o '(TCP|UDP).*$' | sort -u

forcefsck · 2011-01-25 12:04:13 5
Displays All TCP and UDP Connections
This is sample output - yours may be different.
0

sudo netstat|head -n2|tail -n1 && sudo netstat -a|grep udp && echo && sudo netstat|head -n2|tail -n1 && sudo netstat -a|grep tcp

brando56894 · 2011-09-08 18:54:36 4
send echo to socket network

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. Show Sample Output
This is sample output - yours may be different.
```
"foo" if it's working
"Ncat: Connection refused." if it's not
```
-1

echo foo | ncat [ip address] [port]

dragonauta · 2012-10-26 10:53:47 7

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Commands tagged udp (6)

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