参考文档 Adcfgclone Fails with RC-40201 at appsTier While Adding a New Node (文档 ID 876359.1) 

现象：
..... 
Target system APPL_TOP mount point []:
Target system COMMON_TOP directory []:
Target system 8.0.6 ORACLE_HOME directory []:
Target system iAS ORACLE_HOME directory []:
Do you want to preserve the Display set to (y/n) [y] ?:y
Do you want to preserve the port values from the source system on the target system (y/n) [y] ?:y

RC-40201: Unable to connect to Database .
Clone Context uses the same port pool mechanism as the Rapid Install
Once you choose a port pool, Clone Context will validate the port availability.

原因 (CAUSE):  
1. /etc/hosts file did not have the primary node IP address and hostname details
2. Following entries were present in sqlnet.ora file which blocked the connection
tcp.validnode_checking = yes
tcp.invited_nodes=(.)

解决方法 (SOLUTION):  
To implement the solution, please execute the following steps :
1. Add the Primary Node IP address and Hostname details  in /etc/hosts file of target node
2. Remove following entries from sqlnet.ora file if available
tcp.validnode_checking = yes
tcp.invited_nodes=(.)

参考： 
Adcfgclone Fails with RC-40201 at appsTier While Adding a New Node (文档 ID 876359.1)
Sharing The Application Tier File System in Oracle E-Business Suite Release 12 (文档 ID 384248.1)
Adcfgclone.pl tier apps Errors with RC-40201: Unable to connect to Database (文档 ID 271250.1)