Re: [lwip-users] UDP fragmentation works or not?

[address@hidden]

Andrey Skladchikov wrote:
> Hello. I try to send an data array throw the UDP in lwip. When data is
> ready, i create a pbuf and link pbuf->payload to my dataarray.
> Next, i send it.
>
> Receiver is C# .NET udp datagram socket. Im receiving data using
> socket.ReceiveFrom().
>
> So. If i send more then 1470 bytes throw UDP, the package not coming
> into socket - no socket.Avaible increases.

If everything else is configured correctly (and you know your C# host 
supports fragmented packets), that suggests a problem with your lwIP 
port or netif driver, as IP fragmentation should work (in current 
versions of lwIP - don't know what you are using).

> Under the sniffer i see the
> package is comed from device, but in one large package (or my sniffer
> construct it from fragments?).

No way to tell without knowing your sniffer. Generally, you should be 
able to tell by the Ethernet telegram length if it is a big packet or 
multiple small packets.


Simon