View network ports

The ICMP and IP protocol belong to the same level (network layer), and its message is also transmitted in the IP packet, and the port
Is the concept of the Transport Layer TCP/UDP protocol, so the ping port is not successful

* * Windows Check the ports
Telnet IP Port
Netstat-na//Display native connection condition and open port
Netstat-nab//shows which programs are created for each connection
Port monitor: Tcpview, Port Reporter, Green Hawk PC Universal Genie, Network Port Viewer, etc.

The use of Nmapwin under Windows can be consulted:
[Url]http://hi.baidu.com/xzqmr/blog/item/67226a8dfde32a13b31bbad3.html[/url]

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* * Linux checks the ports:
First, using the NMAP scanning machine open port
Nmap-stu localhost//check which ports my own machine is open
NMAP-SP 192.168.32.0/24//Check how many "alive" machines I have in My network segment

Parameter description:
-ss/st/sa/sw/sm:tcp Syn/connect ()/ack/window/maimon Scans
More practical, there are the following three:
A SYN Scan, also known as a semi-open scan, does not open a full TCP connection and executes quickly:
Nmap-ss 192.168.32.0/24
When the SYN scan is unavailable, the TCP Connect () scan is the default TCP scan:
Nmap-st 192.168.32.0/24
UDP scanning with the-SU option, the UDP scan sends an empty (no data) UDP header to each destination port:
Nmap-su 192.168.32.0/24

Second, use Netstat to see the system's listening port

# NETSTAT-ANTP//All connections, digital display host, port, TCP connection, listening program
# Netstat-anup//All connections, digital display host, port, UDP connection, listening program
# Netstat-s//Statistics of all connection data (starting up to date), including TCP, UDP, etc.
# Netstat-st//Statistics all TCP connection data
# NETSTAT-SU//Count all UDP connection data
# NETSTAT-SU//Rough Statistics Connection data

* * Refer Link:
http://snailwarrior.blog.51cto.com/680306/137291 Linux View machine open ports

View network ports