TNS-12225: TNS:destination host unreachable


Sometimes You can get “TNS-12225: TNS:destination host unreachable  ” error.


Details of error are as follows.

TNS-12225: TNS:destination host unreachable
Cause: Contact can not be made with remote party.
Action: Make sure the network driver is functioning and the network is up.

If the Network driver is broken and network is down, you can get this error. So you need to make sure network is up and enabled.

Sometimes you can get this error because of Firewall issues.


Or If database server is down, you can also get TNS-12225: TNS:destination host unreachable.

You should make sure you are trying the right Connection string ( IP or hostname, Port and Service name or SID ).


Or You should check the SElinux settings, SELINUX should be always disabled as follows.

[oracle@msdbadm01 ~]$ cat /etc/selinux/config

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
# SELINUXTYPE= can take one of three two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected.
#     mls - Multi Level Security protection.


And also check the firewall settings, firewall should be disabled, you can disable it as follows

service iptables stop
chkconfig iptables off

service ip6tables stop
chkconfig ip6tables off

You can disable firewall in Redhat with below script.

systemctl stop firewalld
systemctl disable firewalld



Do you want to learn more details about RMAN, then read the following articles.


About Mehmet Salih Deveci

I am Founder of SysDBASoft IT and IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress [email protected].-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  [email protected] a mail atabilirsiniz.

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