[Guy Harris <guy@xxxxxxxxxxxx>]

Fabiana moreno wrote:
> oh...well the machine where the darwin streaming is running is linux. 
> fedora 8 distribution...

You should probably ask the Fedora people how to get the IP stack to add 
an IP ID (assuming the Darwin Streaming Server isn't doing something 
weird such as using a raw socket and constructing its own IP headers).

> but i think every packet should have an id, or 
> am i wrong?

I was surprised when I saw your trace, but, when I looked at RFC 791, it 
didn't seem to prohibit leaving the IP ID as 0 for packets with "don't 
fragment" set, and the only thing RFC 1122 says about the identification 
field is

	When sending an identical copy of an earlier datagram, a host MAY 
optionally retain the same Identification field in the copy.

so there's nothing I can see that would require that, even for packets 
with "don't fragment" set, packets not all be given the same ID value.