Netcat - Revision history

Goldbolt at 19:15, 18 November 2024

2024-11-18T19:15:28Z

Goldbolt at 15:51, 8 August 2023

2023-08-08T15:51:26Z

Goldbolt at 21:20, 23 November 2020

2020-11-23T21:20:17Z

Goldbolt: Created page with "The nc (or netcat) utility is used for just about anything under the sun involving TCP or UDP. It can open TCP connections, send UDP packets, listen on arbitrary TCP and UDP p..."

2020-11-23T21:19:36Z

Created page with "The nc (or netcat) utility is used for just about anything under the sun involving TCP or UDP. It can open TCP connections, send UDP packets, listen on arbitrary TCP and UDP p..."

New page

The nc (or netcat) utility is used for just about anything under the sun involving TCP or UDP. It can open TCP connections, send UDP packets, listen on arbitrary TCP and UDP ports, do port scanning, and deal with both IPv4 and IPv6. Unlike telnet(1), nc scripts nicely, and separates error messages onto standard error instead of sending them to standard output, as telnet(1) does with some.

Common uses include:

â€¢ simple TCP proxies

â€¢ shell-script based HTTP clients and servers
â€¢ network daemon testing
â€¢ a SOCKS or HTTP ProxyCommand for ssh(1)
â€¢ and much, much more

The options are as follows:

-4' Forces nc to use IPv4 addresses only.

-6' Forces nc to use IPv6 addresses only.

-D' Enable debugging on the socket.

-d' Do not attempt to read from stdin.

-h' Prints out nc help.

nc - arbitrary TCP and UDP connections and listens

nc [-46DdhklnrStUuvzC] [-i interval] [-p source_port] [-s source_ip_address] [-T ToS] [-w timeout] [-X proxy_protocol] [

-x proxy_address[ :port]] [hostname] [port[s]]

=Network Speed Test=
Set one server to listen on port 5000 (after opening the port):
nc -vvklnp 5000 >/dev/null

Run this on the other server to test the network speed between the two and change out the XX for the proper IP:
dd if=/dev/zero bs=1M count=1K | nc -vvn 192.168.1.XX 5000 -q 1

← Older revision		Revision as of 15:51, 8 August 2023
Line 69:		Line 69:

	port[s] can be single integers or ranges. Ranges are in the form nn-mm. In general, a destination port must be specified, unless the -U option is given (in which case a socket must be specified).		port[s] can be single integers or ranges. Ranges are in the form nn-mm. In general, a destination port must be specified, unless the -U option is given (in which case a socket must be specified).
		+
		+	=Check Ports=
		+	Check to see if port is open and get a response:
		+	nc -zv IPADDRESS 443

	=Network Speed Test=		=Network Speed Test=

@@ Line 3: / Line 3: @@
 Common uses include:
-             â€¢ simple TCP proxies
+              â€¢ simple TCP proxies
      â€¢ shell-script based HTTP clients and servers

@@ Line 20: / Line 20: @@
      -d' Do not attempt to read from stdin.
      -h' Prints out nc help.
-nc - arbitrary TCP and UDP connections and listens
+    -i interval
-     nc [-46DdhklnrStUuvzC] [-i interval] [-p source_port] [-s source_ip_address] [-T ToS] [-w timeout] [-X proxy_protocol] [
+     -k' Forces nc to stay listening for another connection after its current connection is completed. It is an error to use this option without the -l option.
-        -x proxy_address[                           :port]] [hostname] [port[s]]
+    -l' Used to specify that nc should listen for an incoming connection rather than initiate a connection to a remote host. It is an error to use this option in conjunction with the -p, -s, or -z options. Additionally, any timeouts specified with the -w option are ignored.
 =Network Speed Test=