ORA-12543: TNS:destination host unreachable

26 thoughts on “ORA-12543: TNS:destination host unreachable”

1. i have a similar problem but i have been unable to find an answer from the net. I have 2 VMs on VirtualBox. Each of them have an oracle 11gr2 runnig. i can ping each other, but tnsping is not working, i can also ping the host succesfully.
   This is what i get:
   tnsping MIGRDB01
   Used parameter files:
   /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/sqlnet.ora
   TNS-03505: Failed to resolve name
   ——————-
   cat /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/sqlnet.ora
   NAMES.DIRECTORY_PATH= (TNSNAMES)
   ADR_BASE = /u01/app/oracle
   ———————————————-
   cat /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/tnsnames.ora
   OLAPDB =
   (DESCRIPTION =
   (ADDRESS = (PROTOCOL = TCP)(HOST = oldbapex.localdomain)(PORT = 1521))
   (CONNECT_DATA =
   (SERVER = DEDICATED)
   (SERVICE_NAME = OLAPDB)
   )
   )

   MIGRDB01 =
   (DESCRIPTION =
   (ADDRESS_LIST =
   (ADDRESS = (PROTOCOL = TCP)(HOST = 10gTo11g.localdomain)(PORT = 1521))
   )
   (CONNECT_DATA =
   (SERVER = DEDICATED)
   (SERVICE_NAME = MIGRDB01)
   )
   )
   ————————————————————-
   This is my listener:
   LISTENER =
   (DESCRIPTION_LIST =
   (DESCRIPTION =
   (ADDRESS_LIST =
   (ADDRESS = (PROTOCOL = TCP)(HOST = oldbapex.localdomain)(PORT = 1521))
   )
   (ADDRESS_LIST =
   (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
   )
   )
   )

   SID_LIST_LISTENER =
   (SID_LIST =
   (SID_DESC =
   (SID_NAME = PLSExtProc)
   (ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1)
   (PROGRAM = extproc)
   )
   (SID_DESC =
   (GLOBAL_DBNAME = OLAPDB)
   (ORACLE_HOME =/u01/app/oracle/product/11.2.0/dbhome_1)
   (SID_NAME = OLAPDB)
   )
   )
   ADR_BASE_LISTENER = /u01/app/oracle
   ————————————————-
   The listener is up and runing in both databases (on different VMs)
   ————————————————————
   the tnsnames can ping itself successfully

   Is there anything wrong with the listener?

   need someone help plz

2. Hi Eric Jenkinson ..

   Excellent blog all the articles are very good, and easy to understand ….

3. Hi,

   I also faced this issue . As per I can remember this error occurred due to @ character was used in the password of my database.

   Plz check once and lets know the result.

   Thanks

   Kamran

4. Thanks Kamran, I did have same Error, but Finally I found it is password matter

5. Thanks a lot kamram, your post helped me. I was wondering to resolve this issue & thank god i got your post & i changed my password & its working now. Thanks a lot

6. Thanks kamran .It is the @ character in password.

7. Thenk yu, Kamran. You was very helpful. Same probs here

8. Hi guys , I’ve got a same issue till now am facing the issue. Just now I’ve understand through your replys how to change password I’ve@ character in between my password could you please explain me detailed info for changing the password…

9. PLZ

   Solution problem oracle error 12543
   first finished password
   and i changed name” hamid@77100
   second appear this problem

   best Regards

10. But I don’t have @ in any of my account passwords, but still the tnsping is not working

11. hi
    I installed two oracle Linux in VMware workstation and I configured both network settings and I can ping two hosts but I couldn’t connect through tns . I have problem with TNS-12543: TNS:destination host unreachable. I can ping host

    plz give me solution

12. Hi Guys,

    I have a @ character in my password, please let me know how to change the password

13. This post is very useful, i have solved the issue

14. Thanx Kamran…

15. Thanks Guys..It is very Useful. Pls dont use @ character in your Password 🙂

16. Thanks a million for the post. The listener on my Virtual box was not working.I followed the steps and found out that the IP address was wrong. I changed it and it worked.

17. Thanks a million for the post. I too get this error due to @ in password.

18. Thanks for the valuable suggestion Kamran it resolved my issue.

19. I have a @ character in my password, please let me know how to change the password

20. issue is having an ‘@’ in password….once removed issue is fixed

21. No need to change your DB password, just skip @ sign in your password and try it will work.

22. Salam brother.. it is the firefire error.
    if we have two vitural machine
    db1
    db2
    issue the following command on db1
    ]$service iptables save
    ]$service iptables stop
    ]$chkconfig iptables off
    similarly issue above command on db2 then
    on db2 issue
    ]$tnsping db1
    and on db1
    ]$ tnsping db2.

23. Hi Guys,

    Me also same problem facing, but I didn’t use @charector symbol in my oracle user password.
    I used two servers in single VMware workstation and I am connecting to server1 database like $sqlplus scott/scott@server1.test.com:1521 from server2.
    plz give me solution.

24. For SQLPLUS:
    ORA-12543: TNS:destination host unreachable
    Solution:
    Give User name: sys as sysdba
    If Original Password contains: Welcome@123
    Give password: Welcome123

25. Hello Rubino,

    I had an issue same as like you.
    Finally i got an issue resolved with disabling firewall and SELinux in linux.
    You can try this solution if you are not using in live environment.

    Thanks

26. I started to see this issue after changing my pwd with ‘@’ character in it. I tried to skip the ‘@’ character as mentioned here but it didn’t work for me and gives the same error. Is there any other way to fix this issue – Change the password