11.2.0.4 database and client.
Getting a program intermittently timing out. Examining the PCAP in wireshark, I see tcp retransmission for the tcp flow at timeout event in a packet capture
Heres the flow
Windows client > external firewall > internal firewall > database
I set up a connection program that runs every 5 seconds. I might get the timeout 2-3 times a day. Examining the PCAP for the timeout event, I track the TCP flow, I see it making the attempt out a source port, followed by 2 tcp retransmissions. The external firewall is showing the start packet from the source client IP/port, I then have a 5 second timeout of no traffic that coincides with a 5 second command timeout in the program at which time data starts flowing again.
If I search the firewall for the start on the port, I can see it make the start attempt, but it doesnt make the return for over 2 minutes. The return is not on the client pcap though. Im guessing its not as the client has opened many streams since it opened the start connection and port has closed at that stage. A good start/accept port exchange would take 1-2 seconds max.
The listener log does not show the connection hitting it for the timeout event.
Internal or external firewalls not showing any drops. no process limits being hit.
Im running a RAC, I tried it on the SCAN and then forced it down the VIP, bypassing the SCAN. Nothing doing. Continuing to see the timeouts.
Anyone any suggestions of what to try? theres a couple of support notes on TCP retransmissions but nothing leading me to the answer here. Running out of ideas.