Netstat command is one of tools used for troubleshooting network connectivity. When used it shows list of all open ports/sockets. In addition to connected ports/sockets it can also list listening sockets that are waiting for incoming connections.
netstat command options
-a: Use this option to list all ports (listening and non listening).
-l: show only listening
-v: Verbose
-r: Routing table for kernel will be displayed using this option
-t: Will show only TCP port information.
-u: Will show only UDP port information.
Example of netstat command use
List all ports using netstat command
Use switch -a to list all ports listening as well as non listening ports.
Syntax
netstat -a
This command list out all ports and can make troubleshooting difficult and you have to find information you are looking for. netstat has several useful options which can make troubleshooting really helpful.
Use switch -a to list all ports listening as well as non listening ports.
Syntax
netstat -a
This command list out all ports and can make troubleshooting difficult and you have to find information you are looking for. netstat has several useful options which can make troubleshooting really helpful.
List all tcp ports using netstat command
Using -at switch will show all (listening and non listening ports) TCP ports.
Syntax
netstat -at
List all udp ports using netstat command
Using -au switch will show all (listening and non listening ports) udp ports.
Syntax
netstat -au
List listening ports using netstat command
Using -l switch will show all listening ports only
Syntax
netstat -l
List all listening tcp ports using netstat command
Using -lt switch will show all listening ports tcp ports.
Syntax
netstat -lt
List all listening udp ports using netstat command
Using -lu switch will show all listening ports udp ports.
Syntax
netstat -lu
List all listening unix ports using netstat command
Using -lx switch will show all listening ports unix ports.
Syntax
netstat -lx
List PID and name of program for the listed ports
Using -p switch will display information of related to program name and pid for specific port. You can use -p switch with any other option of netstat
Syntax
netstat -lxp
netstat -atp
List details without hostname in netstat output
Using -n switch will display netstat information without resolving hostname, only ip address will be shown. You can use -n switch with any other option of netstat.
Syntax
netstat -lxpn
netstat -atpn
Print network statistics with netstat command
Using -s switch will display network statics for particular protocol. It will display information like packets received and packet transmitted by particular protocol.
Syntax
netstat -s
To print statistics for any particular protocol use switch -s with switch for a particular protocol like -t for tcp and -u for udp.
Syntax
netstat -st
netstat -su
