Open Ports on Windows XP

[jean-paul martell]

Does any one know how to check the open port on windows xp. I have connect my computer in network and i want to know which ports are active. Like port 123 is used by the Windows Time Service. Any command which will display all listing ports on windows?

[Calvin K]

Open a command line window : Go to Start menu then select Run and type cmd and press Enter and Type:

netstat -an

[Lillebror]

When a specific port is registered it is usually assigned for both TCP and UDP even though only one or the other may be required.To see a list of open ports on Windows XP Got Start >Run >type "cmd" {enter} and type "netstat -a" {enter}.

[Wynn]

• To manually open a port, follow these steps: Click Start, and then click My Network Places.
• Under Network Tasks, click View Network Connections. (Or, right-click My Network Places on the desktop, and then click Properties.)
• Right-click the connection that you use for the Internet, and then click Properties.
• Click the Advanced tab, and then click Settings.
• Click Add to open a new port.
• In the Description box, type a friendly name. For example, type File Sharing : Port 445.
• In the Name or IP address of the computer hosting this service on your network box, type 127.0.0.1.
• In the External port and Internal port boxes, type the port number. Generally, this number is the same.
• Click either TCP or UDP, and then click OK.
• Repeat steps 1 through 9 for each port that you want to open.

[tho_mee]

hai
I wanted to use UDP port 123 for receiving NTP packets from another device in a local LAN set up involving 3 systems. When I tried to bind this UDP port number with a socket which I created in VC++(socket(),bind()..) I was getting bind failed error. So I tried netstat -ano and I saw that port was being listed, but not in LISTENING or any status. So since the port is already open maybe because of that bind failed. I went ahead and stopped the Windows Time service. Then I tried to bind again , but even then it is failing.
I don't know whether my approach is correct or not.
Is it like if you can have this Windows time service running and the system will automatically receive any NTP packets sent by another device(not a Windows server but that device is also using NTP protocol).So I don't have to create a new socket? But even then the socket 127.0.0.1 123 is not showing any status when I do netstat -ano So how do I ensure that it is listening.
Again I have left the firewall off.

[nitesh mehta]

You can try to have a look at the network connection to the peer, if NTP is running on the peer, if the peer itself is synchronized to a stable time source, and if NTP packets from the peer have passed validity tests specified in the RFC1305 etc. TimeTools Windows Atomic Clock NTP Server Syslog Daemon is a free utility that runs on any Windows NT/2000/XP/2003 workstation or server. Setting the Clock and NTP Like all network hardware the PIX has an internal clock that needs to be set correctly for logging reason, certificate.

[tho_mee]

hai

How can I configure my system to receive NTP time syc packets from an external source ?
I have the Win32Time service running in my WinXP PC. The I went to command promt and tried

net time /setsntp:
net time /setsntp:192.168.112.100 //the IP of the h/w unit which will be sending the NTP packets.
net time /querysntp

Even now no luck...
I changed the time in my system and checked it was not sync with that h/w unit.

[EINSTEIN_007]

To configure an internal time server to synchronize with an external time source, follow these steps:

1. Change the server type to NTP. To do this, follow these steps:
Click Start, click Run, type regedit, and then click OK.
Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\Type
In the right pane, right-click Type, and then click Modify.
In Edit Value, type NTP in the Value data box, and then click OK.

2. Set AnnounceFlags to 5. To do this, follow these steps:
Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config\AnnounceFlags
In the right pane, right-click AnnounceFlags, and then click Modify.
In Edit DWORD Value, type 5 in the Value data box, and then click OK.

More information here.

[tho_mee]

hi
these values are set in my PC.
Is there any issues for XP to sync with an external h/w unit?