Re: [lwip-users] Debugging a hang in an lwIP-based application

[tomek wilkxt]

While we're at it, I have one more question. After the fix described
above the application is running much much better and the connection
looks a lot more stable/reliable. But I do still see some rare
occurrences of TCP retransmissions and duplicated ACKs in Wireshark
(like maybe once/twice in an hour or something like that). The hardware
side of the connection in my case is pretty simple - my PC is connected
with a cable to a router, which is connected with a cable to a switch,
which is then connected with a cable to the devices (there are four of
them). I have very little experience with debugging network
connections, so I would like to ask whether this (low) amount of
retransmissions and duplicated ACKs is something normal/expected or
rather something I should worry about, as any number higher than zero
is a symptom of some problem?

Such a rare occurrence is quite normal, but if you have a port mirroring on the switch, then there will be many such duplicates.

--

pozdrawiam
tomek