How to know which ports on my (windows) PC are open or closed?

any one please tell me how to know which ports on my (windows) PC are open or closed i have gone through the "netstat" but its showing the listening ports but i am not able to know which application is using which port

i have also googled for some port scanning tools i found different varities
can any one tell me which on is the best and freely available open source tool.

thanks in advance

kk

sysinternals port scanner

hit symantec.com and look for online vulnerability scanner

best udp scanner

I guess if you use the software called SYGATE firewall, it'll tell you what ports are scanned and what ports are open etc..
I use it on my pc.. It has prevented 8 trojan attacks till now!..

sysinternals port +scanner

no no i dont want any firewall tool
i just need a tool which shows what all ports on my pc are open at a particular instant and which program is using that particular port.

Re: TCP UDP port scanner

I don't know if you still looking... Anyway, use this comand from a cmd shell:

netstat

This show network active connections, like tcp and udp ports, the local IP address, the remote IP address and the state of the port.

To see all the ports use the -a swith, to see the number of the port and the atual IP address not the resolved names use the -n swith. So the command u are looking for looks like this:

netstat -an

The result should look like this:

Proto Dirección local Dirección remota Estado
TCP 0.0.0.0:135 0.0.0.0:0 LISTENING
TCP 0.0.0.0:445 0.0.0.0:0 LISTENING
TCP 10.10.10.164:139 0.0.0.0:0 LISTENING
TCP 127.0.0.1:1026 0.0.0.0:0 LISTENING
UDP 0.0.0.0:445 *:*
UDP 0.0.0.0:500 *:*
UDP 0.0.0.0:1032 *:*
UDP 0.0.0.0:1038 *:*
UDP 0.0.0.0:1055 *:*
UDP 0.0.0.0:1069 *:*
UDP 0.0.0.0:4500 *:*
UDP 10.10.10.164:123 *:*
UDP 10.10.10.164:137 *:*
UDP 10.10.10.164:138 *:*
UDP 10.10.10.164:1900 *:*
UDP 127.0.0.1:123 *:*
UDP 127.0.0.1:1025 *:*
UDP 127.0.0.1:1042 *:*
UDP 127.0.0.1:1590 *:*
UDP 127.0.0.1:1621 *:*
UDP 127.0.0.1:1900 *:*

As you can see it shown the protocol type (TPC or UDP), the local IPort, the remote IPort and the conection state (LISTENING, ESTABLISHED, TIME WAITING, etc...) The opened ports are the ones that show LISTENING state.

Hope this was helpfull.

Re: TCP UDP port scanner

I recently used a Microsoft tool called "port reporter." It will tell you what you need to know in excruciating detail. It is installed as a service. You start/stop the service whenever you want, and it reports on activity between start/stop.

TCP UDP port scanner

Use Ethereal
The world's most popular network protocol analyzer
from https://www.ethereal.com/

Enjoy

Re: TCP UDP port scanner

Ethereal is dead. Use wireshark.

Re: TCP UDP port scanner

see this one:
https://technet.microsoft.com/en-us/sysinternals/bb897437.aspx