sqlplus remote connection giving ORA-21561
If you are using Mac add local computer name to your 127.0.0.1 in /etc/hosts
It will be like
127.0.0.1 localhost <local_computer_name>
Way to find local computer name
System Preferences>Sharing(search for it if you cant find) on the top you can see your local computer name
or you can use "hostname" command to get local computer name
Append the name of your server to the hosts file.
If your /etc/hosts file looks like this:
127.0.0.1 localhost localhost.localdomain
It should be changed to:
127.0.0.1 localhost localhost.localdomain hostname
hostname can be obtained from the command "hostname".