Today we handed over a newly
created database on a newly built server to application team for their testing
and operations. We completed all the procedures before handing over the
database to the apps team which includes registering of database in the listener.
Application team started to log in to the system using SQL Developer to get the
following error.
Application team members called us to help them
resolve the issue. So at the first glance I couldn't guess anything regarding
the issue as it states IO Error. So I took the case and tried to figure out
what is wrong with this.
I tried to ping the server
from my system remotely to which it was successful.
Next step is to edit the
tnsnames.ora file to include the tns entry for the connection and try tnsping.
Now I tried tnsping from my system after editing the tnsnames.ora file but to
get an error.
This error says destination
host unreachable.
Checking the host server and
the listener status.
We just pinged the server and
also listener is running fine on the server and also we are able to connect to
the database using connect string from the same server as below.
A general search on the
Oracle support docs gave the exact problem, cause and the solution.
MOS note id “TNSPING fails
with TNS-12543: TNS:destination host unreachable [ID 1556918.1]” suggested the
cause as
This might be a network issue with either the underlying transport
not being able to contact the host, or a firewall is blocking this client or
connection.
Make sure the network is functioning correctly.
So the fix would be to
contact the OS/Network admin. Hence I involved the OS admin to fix the
networking issue after explaining what’s happening with the issue.
OS team then confirmed that iptables process is running on the server which is a
firewall package in Linux. So once after stopping the iptables process, we are
now able to connect to the database from remote servers.
The problem is resolved. :-) Happy troubleshooting!!
