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

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