sqlplus remote connection giving ORA-21561

Question

I have installed sqlplus based on instruction given here

sqlplus \'username/password@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.0.100)(PORT=1521))(         


        

Answer 1

This issue can also be cause by wrong permissions on the /etc/hosts file. If it is not readable for the Oracle uid, the errors will show.

Make sure your /etc/hosts is readable by everybody:

$ ls -l /etc/hosts
-rw-r--r--    1 root     system        7446 Mar 28 23:03 /etc/hosts 
$

Answer 2

Answer obtained here.

1 - Get your hostname:

$ hostname

new-host

2 - Change the contents of /etc/hosts:

$ sudo cat /etc/hosts

127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain

::1 localhost localhost.localdomain localhost6 localhost6.localdomain6

$ sudo nano /etc/hosts

$ sudo cat /etc/hosts

127.0.0.1 localhost new-host

::1 localhost localhost.localdomain localhost6 localhost6.localdomain6

Hope this helps (:

Answer 3

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

Answer 4

try this, don't put single quotes

sqlplus username/password@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.0.100)(PORT=1521))(CONNECT_DATA=(SID=ORCL)))

Answer 5

look at /etc/sysconfig/network change if needed the hostname

Answer 6

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".