Why is My Java Program Unable to Ping Remote Hosts Despite Disabling the Firewall?-javaTutorial-php.cn

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Why is My Java Program Unable to Ping Remote Hosts Despite Disabling the Firewall?

Susan Sarandon

Oct 25, 2024 pm 02:58 PM

Why is My Java Program Unable to Ping Remote Hosts Despite Disabling the Firewall?

How to Ping an IP Address in Java

When attempting to ping an IP address in Java using the InetAddress.isReachable() method, you may encounter an issue where pinging localhost is successful, but other hosts report as unreachable. This problem can persist even after disabling the firewall.

Possible Solution:

The InetAddress.isReachable() method typically uses ICMP ECHO REQUESTS to determine reachability. However, according to the javadoc, if the necessary privileges (usually administrative rights) cannot be obtained, the method will attempt to establish a TCP connection on port 7 of the destination host.

Therefore, if you are unable to ping remote hosts, consider ensuring that your program has the necessary permissions to perform ICMP operations.

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