UGN Security Forums UGN Security: Knowledge Base Programming VB DHCP detection

hey,

Well I need to write a routine to detect if an Ip is static or dynamic over a LAN, well giz suggested that DHCP addresses are usually dynamic and non DHCP is static, well how would i go about writing a detection routine on if DHCP is enabled or not?

Any suggestions?

well, since I don't know how to do it via API - you may consider looking directly in the registry. This means you will have to know where to look for each windows version. In Win2K, I have found the following two keys:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{3D8B8D97-AE67-4522-AF6C-F2CF52B8243A}\Parameters\Tcpip\
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\Services\{3D8B8D97-AE67-4522-AF6C-F2CF52B8243A}\Parameters\Tcpip

Each time the value was stored in "EnableDHCP", which is a dword value set to 0 for false, and 1 for true. I trust you know how to use the registry API?

Cheers SR!

Never thought about looking in the registry!
And yeah I know how to process the registry!

Tx Again, now if anyone has a win98 box and could source those keys out for me with the full path that would be great cause i have no box running 98 within my reach

well, I did some snooping around in the registry on my roommates 98 running laptop. No luck. I may have to go look at some more DHCP API's or...

say what it is that this is for? Perhaps I can find an alternative solution.

See I am writing a plugin for the OfficeChat app i had been writing for quite some time, basicaly this plugin searches your disk(s) for mp3 files and then creates a Access db file with the ID3 Information of the files and where they are located by network path (eg. //mycomp/c/mp3/lamer.mp3) but i want to create the network paths by IP address rather than host name, now there is no problem in doing that but I found that some machines on the LAN have dynamic IP addresses(most likely by DHCP being enabled). The idea is to be able to use the same app as a Internet and WAN app so hostnames wont do the job.

So by knowing what if the IP addresses are static or dynamic I can implement a scanning routine to see if the IP has changed since last usage of the app, if it has the DB needs to be updated with new paths, and rather than having the user archive all their files again (which with over 200 files can take a [censored] of a time) I would write a loop that replaces the old IP with the new one through using a string var.

Now what happens is that with the plugin you can stream mp3s over the LAN/WAN or whatever by just searching throug each users mp3 archive(DB) and drag and dropping the files to ur mp3 player.

Does it make sense what I just wrote?

Well you might think, why does he not write a piece of code that will change the DHCP settings. Well i noticed that some comps need DHCP active cause of certain things they do, god knows what, and I dont want to [censored] to much with the users comps settings.

Get it?

Well thats why!

can't you make it interchangeable? Where you can use either IP or computer name?