Re: [lwip-users] PING problem

[Jens Nielsen]

It's much easier to analyze if you attach the wireshark capture instead 
of screenshots of the wireshark capture (or both if you insist)

Sounds to me like your driver doesn't feed lwip incoming packets as they 
arrive. A classic error is to signal a semaphore from interrupt and then 
from a task process only one packet before waiting on semaphore again. 
If two packets arrive (two interrupts) before task is woken, the second 
packet and all packets thereafter will be delayed and the symptoms will 
look something like this

In any case: check your driver or add debug to find where your packets 
are delayed

/Jens

On 2019-12-24 07:16, ttc wrote:
> I have the following problem with lwip-2.1.2
>
> I have implemented the socket API so that it can be used, but in rare cases
> the connection is broken.
> While investigating the cause, I discovered that the PING response was
> interrupted on the way.
> Attach the image at that time.
> <http://lwip.100.n7.nabble.com/file/t2330/ping.jpg>
>
> When ping became abnormal, we logged with waireshark.
> <http://lwip.100.n7.nabble.com/file/t2330/wireshark.jpg>
>
> If you check the log, you can see that the reply is delayed for the request.
> For example, a reply of No. 165 is returned for a request of No. 149.
>
> I think Requests and replies are recorded alternately under normal
> conditions, but there are some places where this is not the case.
>
> what I can see to understand the problem?
>
>
>
> --
> Sent from: http://lwip.100.n7.nabble.com/lwip-users-f3.html
>
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