(see the link posted by Mikael for example) If you really want to get all IPs you should loop a ping for your subnet. The Problem with arp is it only lists IP-Addresses your system is aware of (it already communicated with). Select Regex.Split(line, => !string.IsNullOrWhiteSpace(i)).ToList() If (!lines.Contains('No ARP Entries Found. ')) Var lines = output.Split(' ').Where(l => !string.IsNullOrWhiteSpace(l)) Var output = p?.StandardOutput.ReadToEnd() Var p = Process.Start(new ProcessStartInfo('arp', '/a ' + baseIp + subnet) String baseIp = ConfigurationManager.AppSettings įor (int subnet = 1 subnet x.Ip.Equals(baseIp+subnet.ToString())) I also try to get IP's using ARP commands 'arp /a' and 'arp -a' but this command is also unable to do the job finally after searching for a while I found a software called 'Advance IP Scanner' and when I run this software it gets all the IP's from local network and the most strange thing for me is that after running the Advance IP Scanner when I run the ARP command 'arp /a' or 'arp -a' it gets all the IP's from my local network.

I have tried a lot of solutions on internet for getting IP's from my local network and all of them have been failed to get all IP's.

Advance ip scan