Good day!
I can help You to get list of available IP list confidently and quickly because I am a certified network engineer (MTCIPv6E/MTCTCE/MTCNA) having over 10 years of experience in configuring, maintaining and troubleshooting of enterprise network devices, firewalls, Linux servers.
I know how to get it just running one command.
Next, you can easily import the list into VB project.