[lwip-users] Connection abort due to max SYN retries reached

[Axel Lin]

Hi,
I'm using netconn API and running with FreeRTOS.
When test my application with current lwip git tree.
I recently found it's easy to get connection abort when I test
connecting web server.
(test by just repeating send http request)

It's easy to get below debug message:
tcp_slowtmr: max SYN retries reached

I tried increase TCP_SYNMAXRTX but it seems does not help.

However, if I switch back to use lwIPv1.4.1 I never hit the "max SYN
retries reached" issue.
Is there any special setting needs to set in lwIPv2 to avoid such problem?
Did I miss something when upgrade to lwIPv2?

Thanks,
Axel