[lwip-users] Re: [lwip] architecture question

[Adam Dunkels]

On Tuesday 08 January 2002 15.45, you wrote:
> I wonder if your problem could be the same as one I had last week:
> Moving from 0.4.1 to 0.5.0 I didn't get any ACKs from lwip when sending
> small TCP segments. I guess that ICMP packets may have the same problem.

No, ICMP packets are not timer driven. The code for handling ICMP echoes 
(pings) just checks the checksums, swaps the IP addresses, changes the ICMP 
type to echo reply, adjusts the ICMP checksum and returns the packet to the 
device driver for delivery. 

Peter, a few things from the top of my head that might be worth checking:

* See if there are any inconsistancies in packet sizes, buffer sizes and such 
between the sioslipif.c code and your lwipopts.h. I just saw that there is a 
pbuf_alloc() in src/unix/netif/sioslipif.c that uses the hardcoded value 128, 
which probably should be set to PBUF_POOL_BUFSIZE instead.

* The PBUF_LINK_HLEN in lwipopts.h should be 0.

* Check if you have missed some configuration options from lwipopts.h. There 
are a few new ones in 0.5, perhaps that is causing you trouble?

* Try increasing a few memory configuration parameters.

* Try swapping pbuf.c with the one from 0.4.1.

/adam
-- 
Adam Dunkels <address@hidden>
http://www.sics.se/~adam
[This message was sent through the lwip discussion list.]