Re: [lwip-users] eCos - PPP - TCP - LwIP

[Kieran Mansley]

On Mon, 2007-02-19 at 07:16 -0800, Ashish Anand wrote:
> [1] No issue of firewall, since I used "service iptables stop".
> 
> [2] When I telnet, I get something similar:
> 
>  ip_input: iphdr->dest 0xfb0000e0 netif->ip_addr 0x401a8c0 (0xe0, 
> >>>>> 0x1a8c0, 
> >>>>> 0xfb00000)ip_input: iphdr->dest 0xfb0000e0 netif->ip_addr 0x100007f 
> >>>>> (0xe0, 
> >>>>> 0x7f, 0xfb000000) 
> >>>>> ip_input: packet not for us. 
> >>>>> ip_forward: not bouncing packets back on incoming interface. 
> >>>>> 
> 
> Except that this time, the (hex) IP address is 192.168.1.4 (board IP)
> instead of the MDNS IP.
> So even these packets are considered "not for us"!
> 
> It's really strange, why all this complication is arising!

I may have got confused here, but let me summarise what I think is
happening:
 - you receive two packets.
 - the first is for a multicast IP address.
 - the second is a SYN to the board IP address.
 - both are rejected as "not for us"

The multicast packet is rejected because it is multicast and we don't
support generic multicast traffic (there are some special cases where it
is supported, but on the whole not).

The second can only be rejected with that error because your board does
not have the IP address you think it does.  The debug statement above
shows the packet's IP address to be 0xfb0000e0 (i.e 14.0.0.251) and the
netif/board IP address to be  0x100007f (ie. 127.0.0.16).  These are
different.  I don't know why neither of them are the 192.168.1.4 address
that you suggest they should be.  Sounds like your board is not getting
configured properly.

Kieran