====== NC (netcat) ======

**General Information**

nc or netcat "is a feature-packed networking utility which reads and writes data across networks from the command line.". 

**Checklist**
  * Distro(s): Any

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====== Useful Options ======

**EL6**
  * -n → do not perform DNS lookups
  * -u → use UDP instead of default TCP
  * -v → verbose
  * -w 3 → wait 3 seconds before timeout of initial connection
  * -z → Scan only


**EL7**
  * -n → do not perform DNS lookups
  * -u → use UDP instead of default TCP
  * -i → Idle read/write timeout (disconnect after successful connection)
  * -v → verbose
  * -w 3 → wait 3 seconds before timeout of initial connection

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====== Examples ======

Netcat examples.

===== Test Port Reachability =====

Test to see if you can open a connection to a port on a remote system.\\
This is useful to see if a firewall has correct rules.

Example: Check the remote system (192.168.1.1) for an open 443/tcp connection
  * EL6<code bash>nc -zvw 3 192.168.1.1 443</code>
  * EL7<code bash>nc -i 3 -vw 3 192.168.1.1 443</code>

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