DB : [INS-20802] Oracle Net Configuration Assistant failed

Error:

When we check the installation logfile we can find below error log

[FATAL] [DBT-06103] The port (5,500) is already in use.
   ACTION: Specify a free port.
Oracle Database Configuration Assistant failed.
Starting 'Oracle Database Configuration Assistant'
[FATAL] [DBT-06103] The port (5,500) is already in use.
   ACTION: Specify a free port.
Oracle Database Configuration Assistant failed.
Starting 'Oracle Database Configuration Assistant'
[FATAL] [DBT-06103] The port (5,500) is already in use.
   ACTION: Specify a free port.

Solution:

When you ping your hostname it will not be reachable

[oracle@testdb] ping testdb
ping: testdb : Name or service not known

Add the full hostname entry in /etc/hosts file & retry the database installation

192.168.1.1 testdb.local.com testdb