Lwip TCP Client disconnect detection. I am unable to detect if my client is disconnected from server. if my server sends the close command then i am able to detect but problem arises when the server stops abruptly or power goes down.

[NMALH]

MCU is STM32F207VIT6 (client)

server is windows application.

LWIP library is used.

Is there any ping command?

[LCE]

Ping:

Yes, there is, and it's "processed" in icmp.c as ICMP_ECHO .

So you must have LWIP_ICMP defined to enable ping, in opt.h .

[NMALH]

already set to 1. Will you please elaborate more.

[Piranha]

https://www.nongnu.org/lwip/2_1_x/tcp_8h.html#a780cfac08b02c66948ab94ea974202e8

Parameters

p The received data (or NULL when the connection has been closed!)

Either that or this:

https://www.nongnu.org/lwip/2_1_x/tcp_8h.html#a1b4f9e3551e575c0ef06d6daa7f06e55