Hi, I've got the problem that I run into this exception "ORA-12571: TNS:packet writer failure", when my service process falls back into a large idle time. As I have learned that the firewall is the main problem as it closes the idle database connection after one hour of idle time, the solution I've found in the internet doesn't apply for my specific problem. Solution I've found so far: https://garethhooper.com/2011/12/11/ora-12571-tnspacket-writer-failure-one-of-the-hardest-problems-ive-had-to-resolve/

I can not set the attribute "SQLNET.EXPIRE_TIME" (other processes forbid it, don't ask why), so I need another solution for this problem. Is there any possibility to manually activate the pooled connections for a ping/keepalive signal?

Could you explain a bit why this is an LLBLGen Pro specific problem, and if so, what version you're using etc. ? Your post solely talks about ODP.NET....