Why Does Java\'s InetAddress.isReachable() Fail to Ping Non-Localhost Hosts?

Troubleshooting Java's Ping Request with InetAddress.isReachable()

When attempting to ping IP addresses using InetAddress.isReachable() in Java, users may encounter "Host is NOT reachable" errors when targeting non-localhost hosts. Despite disabling firewalls, the issue persists.

Upon examining the documentation for InetAddress.isReachable(), it is revealed that it typically employs ICMP ECHO REQUESTs, which often necessitate root privileges.

Resolution

To resolve this issue, one must ensure they possess administrative privileges. If this is not feasible, an alternative solution would be to utilize TCP port 7 for connection establishment, as it does not require elevated permissions.

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