Siebel Tools >  Siebel Tools Not Able To Connect Local DB After DYNAMIC_REGISTRATION_LISTENER = OFF In XE

Siebel Tools Not Able To Connect Local DB After DYNAMIC_REGISTRATION_LISTENER = OFF In XE

APPLIES TO:
Siebel CRM - Version 16.18 [IP2016] and later

Siebel tools not able to connect local DB after DYNAMIC_REGISTRATION_LISTENER = OFF in XE

Recently customer upgraded to IP16 from IP13. They are using Oracle XE for local DB to connect Siebel tools.
As per the corporate ethical hacking team and Oracle recommendations, they need to disable dynamic registration. They have set below parameters in listener.ora file.
DYNAMIC_REGISTRATION_LISTENER = OFF
After this settings we are not able login local DB using Siebel tools.

They are able connect to server using Siebel tools as it will using DB2 connect. Only issue is with local DB as they are using Oracle XE.

Need to know if any settings have to be changed.

ERROR
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Unable to login to Local DB using Siebel Tools.

STEPS
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The issue can be reproduced at will with the following steps:
1. Launch Siebel Tools
2. Try to login using Local DB

CAUSE
Issue was caused due to missing entry in listener.ora file.
A missing entry corresponding to Oracle XE was preventing customer from login to Siebel Tools.

SOLUTION
Add this entry in listener.ora file
DEFAULT_SERVICE_LISTENER = (XE)

Also, add Oracle XE SID to listener.ora file.