One cause leads to the error(The specified nodes are not clusterable)

Today when I installed a new Oracle RAC DB, an error occured which is about "The specified nodes are not clusterable".

The cluster nodes are in a domain network, and the public/private/virtual name are all with the domain name.

Before I run the SHELL script .runInstaller.sh, I only run the security authentication commands to identify these issues:

ssh node1.domain.com date
ssh node2.domain.com date
ssh node1-priv.domain.com date
ssh node2-priv.domain.com date

But I didn't run the command like that:

ssh node1 date
ssh node2 date
ssh node1-priv date
ssh node2-priv date

So I got the error. Anyway, It's so weird,but it's a good stuff for you to guide installation.