Error TNS-12543

Error TNS-12543 while connect to a remote database on a Linux

Issue:

Environment

Source: rac1 192.168.2.101
Target: rac2 192.168.2.102

[oracle@rac1 ~]$ tnsping CDB1_DG

TNS Ping Utility for Linux: Version 12.2.0.1.0 - Production on 18-JUL-2018 10:53:54

Copyright (c) 1997, 2016, Oracle.  All rights reserved.

Used parameter files:
/u01/app/oracle/product/12.2.0.1/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.2.102)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = CDB1_DG)(UR = A)))
TNS-12543: TNS:destination host unreachable
[oracle@rac1 ~]$

Action Plan:

-- Verify Firewall on target database
-- logon to RAC2 (192.168.2.102)

[root@rac2 ~]# hostname
rac2.rajasekhar.com
[root@rac2 ~]#
[root@rac2 ~]# service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
num  target     prot opt source               destination
1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED
2    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0
3    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
4    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22
5    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited

Chain FORWARD (policy ACCEPT)
num  target     prot opt source               destination
1    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source               destination

[root@rac2 ~]#
[root@rac2 ~]# service iptables stop  <--- turn off firewall
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Unloading modules:                               [  OK  ]
[root@rac2 ~]#
[root@rac2 ~]# chkconfig iptables off
[root@rac2 ~]#
[root@rac2 ~]# service iptables status
iptables: Firewall is not running.  <-----
[root@rac2 ~]#

[oracle@rac1 ~]$ tnsping CDB1_DG

TNS Ping Utility for Linux: Version 12.2.0.1.0 - Production on 18-JUL-2018 11:05:12

Copyright (c) 1997, 2016, Oracle.  All rights reserved.

Used parameter files:
/u01/app/oracle/product/12.2.0.1/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.2.102)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = CDB1_DG)(UR = A)))
OK (0 msec)
[oracle@rac1 ~]$

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Thank you,
Rajasekhar Amudala

2 thoughts on “Error TNS-12543

  1. Hi ,

    We are facing same issue on prod db server but we can’t stop the firewall so how can we add the ip entry in the iptables

    1. Hello Sikandar –

      Thank you for asking question. Please find the inputs.

      1. Please check with Unix Admin is there any impact when you want to stop firewall.. However it has to be done by user root.
      2. If say no.. Please log a ticket with Oracle Support…and explain your problem and get the solution..if they confirm to disable firewall.. then you can proof to Unix Admin..

      Thank you,
      Rajasekhar

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