Finding computers

[mad_fox9007]

I'm running an windows xp box connected to my schools network. When I hit enter without typing anything in the "find computers" option in the search menue I get a list of all the computers in my work group which happens to be all the computers currently online in my dorm. My question is how does windows find thoes computers?

[sdewis]

Hi there

You haven't supplied many details, but I would guess that your network is using a Windows 2000/2003 server domain. When you do "find computers", the PC sends out a "broadcast" packet to ask for a reply from active computers. After a timeout (when the PC stops listening for replies), the PC will present you with a list of computers on your local network which responded to the original "who's there?" request.

Depending on network configuration, the PC may directly interrogate Active Directory to find a list of active computers.

Hope this helps

Sean

[mad_fox9007]

Thats just what I was looking for, thanks.

[SirDice]

Several ways pop to mind and it really depends on how your school's network is setup..

a) By using UPnP (Universal Plug aNd Play)
http://support.microsoft.com/kb/323713/en-us

b) By using the Computer Browser service
http://support.microsoft.com/kb/188001

c) By using Active Directory
http://www.microsoft.com/technet/pro...f25cd6d55.mspx

[SirDice]

Several ways pop to mind and it really depends on how your school's network is setup..

a) By using UPnP (Universal Plug aNd Play)
http://support.microsoft.com/kb/323713/en-us

b) By using the Computer Browser service
http://support.microsoft.com/kb/188001

c) By using Active Directory
http://www.microsoft.com/technet/pro...f25cd6d55.mspx

[mad_fox9007]

How could i search for, or list the computers in my active directory using java?

[mad_fox9007]

How could i search for, or list the computers in my active directory using java?

[the_cephexin]

In order for your first question:

Computers usually use a method called HOST DETECTION to validate a host's existence. If the ICMP gets closed on a network (for example), then many of the Scanners and Tracers gets failed.

so in this situation you can use other Advanced Host Detection (and verification) to perform host detection, for example:

Sending a SYN packet to a closed port: In this situation the target host will discard the sent packet and you can detect its existence by this activity.

If you need more details, I can continue ...

Such techniques usually used on the Network Scanners and you can develop them (if they're Open Source) and know programmming.

[the_cephexin]

In order for your first question:

Computers usually use a method called HOST DETECTION to validate a host's existence. If the ICMP gets closed on a network (for example), then many of the Scanners and Tracers gets failed.

so in this situation you can use other Advanced Host Detection (and verification) to perform host detection, for example:

Sending a SYN packet to a closed port: In this situation the target host will discard the sent packet and you can detect its existence by this activity.

If you need more details, I can continue ...

Such techniques usually used on the Network Scanners and you can develop them (if they're Open Source) and know programmming.

[mad_fox9007]

in java i can send a message to all the computers on my local network if i send a udp broadcast packet, but i am having trouble assigning 255.255.255.255 to an InetAddress, i'm not sure of the correct syntax, and i have spent plenty of time googling it, and suggestiongs?