Yes the gateway is correctly set. I was expecting to see the traffic using
the promiscuous mode of my adapter, as I am able to capture packets that
their destination is other than my PC.

Running the server on the same PC is not an option, since as I stated
everything works perfectly then. The problems start when I want to reach an
external server.


*Fotis Panagiotopoulos*


*--*

*AMCO S.A.*

25 Amfiaraou st. PO 10442, Athens, Greece
Tel: +30 210 5907000 ext. -34 <%2B30%20210%205907000%20ext.%20-36> | Fax: +30
210 5912711
e-mail: [email protected] | web: http://www.amco.gr

On Mon, Jul 25, 2016 at 7:37 PM, Chris Williams <[email protected]>
wrote:

> Quoting Fotis Panagiotopoulos <[email protected]>:
>
> You talk about wireshark. If you are running wireshark on a PC, you will
> not see the attempt to connect to a remote server from your device. The
> switch or router you are using will not send any of that traffic to the PC
> unless you provide a special routing. I have a router that has a debug
> output that will copy all traffic to a debug port which I then monitor with
> the PC.
>
> If you can run the server on the SAME PC as wireshark then you will see
> the traffic.
>
> Alternatively, have you provided a gateway address? For routes external to
> the local network the gateway address is needed.
>
> Does that explain anything?
>
> Regards,
>
> Chris.
>
> Hi,
>>
>> I am using LWIP 1.4.1 for a microcontroller project, based on the NXP
>> LPC1769 MCU. I do not use an RTOS and thus I am using the raw API.
>>
>> I created the device drivers mostly based on the examples provided by NXP.
>>
>> While a try any connection to my LAN, everything works perfect. However
>> each time I try to connect to a server external of my local network
>> (internet) LWIP does not generate any traffic at all, as seen by
>> wireshark,
>> and all connection attemps fail.
>>
>> I already have tried connecting to many different servers, which are
>> confirmed to operate correct, and I also tried the provided DNS module. I
>> tried both TCP and UDP connections and all fail with no traffic on my
>> network at all.
>>
>> I double checked for any firewalls in my router or ISP, and everything
>> seems normal. I also tried in various different networks (2 DSL lines, and
>> through one 3G router), with the same outcome every time.
>>
>> All addresses are double checked to be correct  (IP, gatway etc...).
>>
>> One thing to note is that after hundrends of tries, randomly I achieved
>> connection with a DNS and an NTP server, with no apparent changes to my
>> code. Even in that cases after a few packets, the connection was again
>> dying requiring a restart of my app. A few tries later with no code
>> changes
>> resulted again in the same problem.
>>
>> Memory management is closely observed, there aren't any memory leaks, nor
>> my application runs out of memory.
>>
>>
>> Are there any ideas for this problem? I suspect my low-level driver, which
>> however operates very good in my local network. How are the packets
>> different when the destination is in a LAN vs WAN?
>>
>> <http://www.amco.gr/>
>>
>>
>
>
> --
> ---------------------------------------------------------------------------
> | Chris Williams    EMail [email protected]
> |
> |                   Web www.chrydesn.co.uk
> |
> |                   Tel/Fax  01686 688065                                 |
> | Chrysalis Design. Electronics, Computers, Hardware, Software.           |
> |                   Design and development to meet all your needs.        |
> ---------------------------------------------------------------------------
>
>
>
>
>
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