Pure Java Network Tools. Free portable cross-platform. ICMP-ping works well only when run as Admin in Windows or Root in Linux ! You can check this by iptraf linux utility. Run as root/admin user ! Include:

1. ICMP-ping,
2. ICMP-traceroute,
3. DNS-check resolver,
4. Host TCP-scanner,
5. IP-calculator,
6. Syslog-server,
7. Local ARP-cache request,
8. Parallel Network Ping-Scanner,
9. Snmp-Get concrete value utility.
10. ICMP flood utility.
11. UDP flood utility.
12. TFTP-server.
13. NTP-server.
14. Host TCP-ping.
15. SNMP-MRTG traffic monitor.
16. Anonymous FTP-server.
17. Parallel Network TCP-scanner.
18. Parallel Network SNMP-scanner.
19. Parallel Network DNS-scanner.
20. Parallel SNMP-DoS.
21. Parallel HTTP/HTTPS-DoS.

Need JRE-1.8: