Month: October 2019

OUI issue NGINST-64002: Error occurred in validation of: “Host Name”

When installing an Oracle application using OUI (Oracle Universal Installer) sometimes it verifies if a given host is reachable. 

Unfortunately, in my case, it was always failing:

All this despite the host was perfectly reachable using Ping:

So what was happening? The OUI is using under the hood Java’s InetAddress.isReachable(). The algorithm is:

  1.  Try to send ICMP “ping”, if that fails
  2.  Try to use ICMP Echo service
Unfortunately, check (1) can only be attempted if you run the app with an elevated permissions (root or sudo), which typically does not happen.
So it goes to (2) and makes the following attempt:

So it probes Echo service over TCP port 7. 


Here you are! It was a missing firewall rule. Just open TCP/7 port on the target (checked) system and the test is passing like a charm.

Details for nerds

A small tool to run the test. Just run it as shown below:

Compare with same test ran using sudo. This time the test is done using ICMP, so no TCP/7 port needed. But as mentioned earlier, this is highly impractical and even not recommended: