Downloading NetPenguin 1.5 from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this software available. The software is included in Internet & Network Tools. We recommend checking the downloaded files with any free antivirus. This software is an intellectual property of Sales@netpenguin.net.
From the developer:
NetPenguin - including following network tools:IP Scanner which can find IP address;LAN Scanner which can scan IP addresses in ethernet LAN;Ping;netstat;Port Scanner;Domain Name Search which can find informations of country and others from DNS,whois server;Packet Sniffer;MAC Address Scanner which can lookup MAC address with a specific IP address;and ARP fastener which could bolt ARP to IP address
You may want to check out more software, such as VMTS ESX Patch Manager or IMsecure, which might be related to NetPenguin.