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Registered: ‎09-30-2015

SDK 2015.2, Zynq, LwIp 1.4.1, loosing connection, standalone

Dear all,
I have observed an issue since I upgrade my project using lwIP 1.4.1, along with the update to SDK 15.2:

I have one application using UDP, one other using TCP.
Both applications are having problems now, with frequent time-outs/reconnects.
By using the former supplied lwIP version I did not experience something like that.
I can improve the behaviour by using a dedicated Ethernet adapter, without other traffic.
Link speed in all cases is 1000Mbps.
I am using a standalone application without operating system.
The application is doing nothing else then Ethernet handling at the moment,
the main loop cycle time is always below 100µs, typical ~5us, in case messages are transmitted ~33us.

The Hardware I am using is the Avnet microzed board.
So far I didn't look into details of the problem, but now I need to fix this.
I have the strong feeling it is related to the internals of the LwIP implementation,
and I have no clue where to start at the moment.

Does someone have an advice how to start debugging on this?


I have seen more posts describing more or less similar issues,

(e.g. )
so maybe it is a good Idea to collect all observations in that direction:

Basically I have 3 facts for this Issue:
    - Before LwIP 1.4.1 or SDK 14.? this effect didn't occur (at least not noticeably frequent )
    - Other Network Traffic has an Influence on this
    - TCP and UDP are effected




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Registered: ‎07-20-2010

Hi Arne,
I have noticed a similar problem when I have upgraded a project from SDK 2014.4 (using lwip 1.4.0 ver 2.3) to SDK 2015.3 (with lwip 1.4.1 ver. 1.2). With lwip 1.4.0 I have not problem. If I force SDK 2015.3 to use lwip 1.4.0 all is running good, but I don't know why. Did you have try lwip 1.4.0?
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