Re: [lwip-users] LPC1769 ethernet problem

[Chris Williams]

Quoting Fotis Panagiotopoulos <address@hidden>:

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 address@hidden                            |
|                   Web www.chrydesn.co.uk                                |
|                   Tel/Fax  01686 688065                                 |
| Chrysalis Design. Electronics, Computers, Hardware, Software.           |
|                   Design and development to meet all your needs.        |
---------------------------------------------------------------------------