Netstat command and usages

The netstat command is a Command Prompt command used to display very detailed information about how your computer is communicating with other computers or network devices.

etstat Command Syntax:

netstat [-a] [-b] [-e] [-f] [-n] [-o] [-p protocol] [-r] [-s] [-t] [-x] [-y] [time_interval] [/?]

-a = This switch displays active TCP connections, TCP connections with the listening state, as well as UDP ports that are being listened to.

-b = This netstat switch is very similar to the -o switch listed below, but instead of displaying the PID, will display the process’s actual file name. Using -b over -o might seem like it’s saving you a step or two but using it can sometimes greatly extend the time it takes netstat to fully execute.

-e = Use this switch with the netstat command to show statistics about your network connection. This data includes bytes, unicast packets, non-unicast packets, discards, errors, and unknown protocols received and sent since the connection was established.

-f = The -f switch will force the netstat command to display the Fully Qualified Domain Name (FQDN) for each foreign IP addresses when possible.

-n = Use the -n switch to prevent netstat from attempting to determine host names for foreign IP addresses. Depending on your current network connections, using this switch could considerably reduce the time it takes for netstat to fully execute.

-o = A handy option for many troubleshooting tasks, the -o switch displays the process identifier (PID) associated with each displayed connection. See the example below for more about using netstat -o.

-p = Use the -p switch to show connections or statistics only for a particular protocol. You can not define more than one protocol at once, nor can you execute netstat with -p without defining a protocol.

protocol = When specifying a protocol with the -p option, you can use tcp, udp, tcpv6, or udpv6. If you use -s with -p to view statistics by protocol, you can use icmp, ip, icmpv6, or ipv6 in addition to the first four I mentioned.

-r = Execute netstat with -r to show the IP routing table. This is the same as using the route command to execute route print.

-s = The -s option can be used with the netstat command to show detailed statistics by protocol. You can limit the statistics shown to a particular protocol by using the -s option and specifying that protocol, but be sure to use -s before -p protocol when using the switches together.

-t = Use the -t switch to show the current TCP chimney offload state in place of the typically displayed TCP state.

-x = Use the -x option to show all NetworkDirect listeners, connections, and shared endpoints.

-y = The -y switch can be used to show the TCP connection template for all connection. You cannot use -y with any other netstat option.

time_interval = This is the time, in seconds, that you’d like the netstat command to re-execute automatically, stopping only when you use Ctrl-C to end the loop.

/? = Use the help switch to show details about the netstat command’s several options.

Netstat Command Examples:

netstat -f

show all active TCP connections connected to in FQDN format [-f] instead of a simple IP address.

Active Connections

Proto  Local Address          Foreign Address        State
TCP    127.0.0.1:5357         VM-Windows-7:49229     TIME_WAIT
TCP    127.0.0.1:49225        VM-Windows-7:12080     TIME_WAIT
TCP    192.168.1.14:49194     75.125.212.75:http     CLOSE_WAIT
TCP    192.168.1.14:49196     a795sm.avast.com:http  CLOSE_WAIT
TCP    192.168.1.14:49197     a795sm.avast.com:http  CLOSE_WAIT
TCP    192.168.1.14:49230     TIM-PC:wsd             TIME_WAIT
TCP    192.168.1.14:49231     TIM-PC:icslap          ESTABLISHED
TCP    192.168.1.14:49232     TIM-PC:netbios-ssn     TIME_WAIT
TCP    192.168.1.14:49233     TIM-PC:netbios-ssn     TIME_WAIT
TCP    [::1]:2869             VM-Windows-7:49226     ESTABLISHED
TCP    [::1]:49226            VM-Windows-7:icslap    ESTABLISHED

netstat -o
shows active TCP connections, but also want to see the corresponding process identifier [-o] for each connection .

Active Connections

Proto  Local Address          Foreign Address        State           PID
TCP    192.168.1.14:49194     75.125.212.75:http     CLOSE_WAIT      2948
TCP    192.168.1.14:49196     a795sm:http            CLOSE_WAIT      2948
TCP    192.168.1.14:49197     a795sm:http            CLOSE_WAIT      2948

netstat -s -p tcp -f
TCP stats [-p tcp] also want the foreign addresses displayed in FQDN format [-f].

netstat -e -t 5
network interface statistics [-e] and I wanted these statistics to continually update in the command window every five seconds [-t 5].

Advertisements

Posted on March 3, 2013, in Uncategorized, Windows. Bookmark the permalink. Leave a comment.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: