Testing a valid IP address? ( SOLVED! )

[Antonio Linares]

JC,

>
Actually, I want to see if an IP location of my local network is available ... if the machine is turned on, for example.
>

You can look for that machine mac address (network card identifier).

[Antonio Linares]

http://forums.fivetechsoft.com/viewtopic.php?t=12596

[JC]

You can look for that machine mac address (network card identifier).

Antonio,

How I can do? With the function getNetCardID()?
But, it returns to me the mac address of my own machine, don't?
I want to verifying if an IP address is valid, if your machine was turned on...

[JC]

http://forums.fivetechsoft.com/viewtopic.php?t=12596

Antonio,

A simple test is very efficient to do it:

Testing the return with getHostByAddress( cNetAddress )... if is empty, IP is not valid or your own machine is turned off.

[Antonio Linares]

Julio,

> getHostByAddress( cNetAddress )

What value do you get for a connected computer ?

The way I commented you is for software protection, to check the server network card id.

[JC]

What value do you get for a connected computer ?

The way I commented you is for software protection, to check the server network card id.

Antonio,

In the true, I want to test if some IP address of my local network is valid... I'm using SQLLIB (from Vailton Renato) for my connections to database, but when always I try to connect with a erroneous ip address... this returns to me a GPF error

So, I think if this is an good way to testing the connection IP before connect!

[Antonio Linares]

Julio,

> this is an good way to testing the connection IP before connect!

Yes, it is

[JC]

Antonio,

Ok, apparently works very fine! Thank you!

[anserkk]

Dear Mr.Julio

In my PC getHostByAddress( cIp ) is always returing empty value. When I try to ping that IP (cIP) from my machine that IP is responding. Any idea what could be the problem ?

Code: Select all

cIp:="192.168.0.164"
if empty( getHostByAddress( cIp ) )
	MsgInfo("IP does not Exists")
else
	MsgInfo("IP Exists")
Endif

Regards

Anser

[JC]

Anser,

The function getHostByAddress() returns the netbios name of the machine... so, one cause of your problem must be the name of machine empty.

You can joke with both functions: getHostByAddress() and getHostByName()

At first, the parameter is a ip valid (or not) and at second, the parameter is the netbios name...

Code: Select all

cIpAddress := "192.168.0.254"
cNetbiosName := "home_pc"

msgInfo( getHostByAddress( cIpAddress ) ) -> returns "home_pc"

msgInfo( getHostByName( nNetbiosName ) ) -> returns "192.168.0.254"

Please, provide a little example of your source code... I will try to help you more.

[anserkk]

Dear JC,

My requirement is same as yours. For eg. I would like to know whether a machine with the given IP is available in the network or not.

Just like when you give ping command in command prompt
For Eg: PING 192.168.0.151

If the machine with the IP 192.168.0.151 exists it will respond back ( Of course they can be firewall and antivirus rules not to respond back )

Regards

Anser

[JC]

Anser,

You are right! The test with getHostByAddress() will be if is empty... so, we can understanding that machine owner of this ip is turned off or the ip is not valid. Like Antonio say...

[anserkk]

Dear JC,

My problem is that when I ping the IP of the networked PC from the command prompt it is reponding back but from FWH functions it is not.

To make it more clear:-

From command prompt I am able to ping that IP and PC responds back
From command prompt I am able to ping that PC with the NetBios name and PC responds back correctly

But with the functions getHostByAddress( cIp ) and getHostByName("PC1"), I am getting false results

My Code

Code: Select all

if empty( getHostByAddress( "192.168.0.162" ) )  // Returning empty
	MsgInfo("IP does not Exists")
else
	MsgInfo("IP Exists")
Endif

if empty( getHostByName("PC1"))  // Returning 0.0.0.0
	MsgInfo("Name PC1 does not exist")
else
	MsgInfo("Name PC1  Exists")
Endif

Is there any other trick to make it fuctional ?

Regards

Anser

[JC]

Anser,

I have understanding you.

I think, maybe your machine needs join on local workgroup or domain.
That way, will be can recognize the name and resolve it to IP.

Try to execute a ping on your machine like this:

Code: Select all

C:\>ping PC1

This command must be responded!

[ukoenig]

Hello Anserkk

What happens with a test, using the tool GETIP ?

Another Test-Tool :

http://www.pflegeplus.com/fw_downloads/gai.zip



Regards
Uwe