Re: [lwip-users] Force PPP TermReq (Lwip 2.0.0 RC2)

[Sylvain Rochet]

Hi Greg,


On Tue, Aug 09, 2016 at 04:21:43PM +0000, Greg Smith wrote:
> 
> I totally agree this would be nice to have a data trace.  I do already 
> have a facility to output printf() data to a console or Telnet 
> session. However, when I turned on all those options (PRINTPKT_SUPPORT 
> was the only one I didn't already have on), I don't see it outputting 
> any packet data during LCP.  Should I be seeing payload bytes during 
> this phase?

Yes, all packets are dumped except IP and IPv6 packets. Are you sure 
lwIP debugging trace works at all ?


> I am running an RS485 bus, so I could hook another device in to 
> "listen" to all the traffic.  Unfortunately, that's going to get me a 
> lot of bytes, but minimal decoding.  Do you know of any good tools 
> where I could dump raw bytes and get packet decoding back out?  (Or 
> even a tool to hang on the serial line and decode live?)

If you can hook on the serial line the easiest way is to use pppd and 
you'll have exactly the same output as lwIP PPP trace, or even better 
lwIP itself using the unix port. If you ask I almost never try lwIP PPP 
support on real hardware, I hate waiting the flash time.

Anyway, I usually write small quick'n'dirty C snippets to do sniffers 
like that, but you really should get lwIP trace working :-)


Sylvain

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