Currently am moving from oracle 184.108.40.206 to 220.127.116.11 then to 11G. Our third party vendor claim that just doing an import from 9i to 11G will do. My claim is to use DBUA. I need to tell him why DBUA is a better approach as it is oracle supported way for upgrading database.
His evil plan is to create a new 11G database and then import the dump obtained from the 9i database. He says as long as the data is there, there shouldn't be any issue.
Then why did oracle create dbua????
DBUA is an automated tool to perform the upgrade process from a specific version of the database - see Preparing to Upgrade Oracle Database
In this case if you are at 18.104.22.168, you cannot use DBUA - you will first need to apply the 22.214.171.124 patch before you can use DBUA.
If you do not want to apply the 126.96.36.199 patch, then you can export from 188.8.131.52 and import into 11gR2 - Moving Data Using Oracle Data Pump