Otherwise you can check fnd_profile_option_values where profile_option_value has an ip style number in it. Check icx_parameters so see whether an vals in there are IP numbers, check the tnsnames and listener.ora files in the oracle homes to see if they have ips or names and a quick check, if someone has not manually updated it ... if you are autoconfig enabled, check the context file ( $APPL_TOP/admin/
Steps :
1. Shut down the Application as well as database.
2. Change the IP address at OS level and restart the Network daemon.
3. Bring up the database listener.
4. Startup the databse.
5. run auto config at databse then at all middle tier starting from admin node. It should complete successfully.
6. Bring up the middle Tier. They should come up without any error.