DBCA Second/last instance startup fails/ generic startup with ORA-03113 in 12.2 due to wrong rp_filter setting for private interconnect interfaces

现象

dbca安装过程报错日志信息

PRCR-1079 : Failed to start resource ora.racdb.db
CRS-5017: The resource action "ora.racdb.db start" encountered the following error: 
ORA-03113: end-of-file on communication channel
Process ID: 79749
Session ID: 1592 Serial number: 36171
. For details refer to "(:CLSN00107:)" in "/home/u01/app/grid/diag/crs/db01/crs/trace/crsd_oraagent_oracle.trc".

CRS-2674: Start of 'ora.racdb.db' on 'db01' failed
CRS-2632: There are no more servers to try to place resource 'ora.racdb.db' on that would satisfy its placement policy

alert日志信息

Using default pga_aggregate_limit of 15000 MB
2021-08-27T01:29:29.568576-04:00
No connectivity to other instances in the cluster during startup. Hence, LMON is terminating the instance. Please check the LMON trace file for details. Also, please check the network logs of this instance along with clusterwide network health for problems and then re-start this instance.
LMON (ospid: ): terminating the instance due to ORA error
Cause - 'Instance is being terminated by LMON'
2021-08-27T01:29:29.755556-04:00
System state dump requested by (instance=1, osid=118601 (LMON)), summary=[abnormal instance termination]. error - 'Instance is terminating.
'
System State dumped to trace file /home/u01/app/oracle/diag/rdbms/racdb/racdb1/trace/racdb1_diag_118582.trc
2021-08-27T01:29:29.931513-04:00
Dumping diagnostic data in directory=[cdmp_20210827012929], requested by (instance=1, osid=118601 (LMON)), summary=[abnormal instance termination].
2021-08-27T01:29:31.038002-04:00
Instance terminated by LMON, pid = 118601

原因：

两个节点的db实例无法交流，其中一个节点被踢出集群

解决：

设置rp_filter参数

编辑/etc/sysctl.conf文件，添加一下信息

net.ipv4.conf.enp0s8.rp_filter = 2
net.ipv4.conf.enp0s9.rp_filter = 2
net.ipv4.conf.enp0s3.rp_filter = 1

说明：

enp0s3：为公网地址

enp0s8，enp0s9为私网地址


rp_filter详解：https://www.cnblogs.com/lipengxiang2009/p/7446388.html