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. Telnet-client,
8. Local ARP-cache request,
9. Parallel Network Ping-Scanner,
10. Snmp-Get concrete value utility.
11. ICMP flood utility.
12. UDP flood utility.
13. TFTP-server.
14. NTP-server.
15. Host TCP-ping.
16. SNMP-MRTG traffic monitor.
17. Anonymous FTP-server.
18. Parallel Network TCP-scanner.
19. Parallel Network SNMP-scanner.
20. Parallel Network DNS-scanner.
21. Parallel SNMP-DoS.
22. Parallel HTTP/HTTPS-DoS.

Need JRE-1.8: