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 ~]# THIS IS TEST MACHINE, HENCE I STOPPED firewall. if you don't to stop then You can you add entry into firewall table to allow connection [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