Re: [lwip-users] Do I have Internet Connection?pppos-GSM

[Patrick Klos]

On 12/21/2018 9:00 AM, arsz6733 wrote:
> here is new data that may help
>
> ping dump that is sent by uart
>
> {7E}{21}{45}{00}{00}{3C}{30}{22}{00}{00}{7F}{01}{39}{83}{C0}{A8}{01}{64}{08}{08}{08}{08}{08}{00}{4C}{15}{00}{01}{01}{46}{61}{62}{63}{64}{65}{66}{67}{68}{69}{6A}{6B}{6C}{6D}{6E}{6F}{70}{71}{72}{73}{74}{75}{76}{77}{61}{62}{63}{64}{65}{66}{67}{68}{69}{10}{8F}{7E}

I didn't check the PPP FCS or the IP checksum, but the packet looks 
reasonable for an IP/ICMP packet.

> and here is the ascii value .. it seems interesting the way it spells
> alphabets!!!!!!!!!
>
> ~!E{00}{00}<0{1A}{00}{00}{01}9‹À¨{01}d{08}{08}{08}{08}{08}{00}L{1D}{00}{01}{01}>abcdefghijklmnopqrstuvwabcdefghiV³~

That could be a typical pattern for a PING request/reply.  If you dumped 
the outgoing packet, you'd probably see the same pattern.

What IP addresses are assigned to your PPP interface and to your 
ethernet interface?

If you could use a debugger to step through the receive code for the 
IP/ICMP packet (or instrument the receive code with some short 
printf()'s), maybe you can see what it's doing with the packet or why it 
might be rejecting it??

Patrick Klos
Klos Technologies, Inc.