[Guy Harris <guy@xxxxxxxxxxxx>]

On Oct 23, 2003, at 10:05 AM, Dinkar Bhat wrote:

> Does "Dropped Packets: 0" in the summary window really mean zero 
> dropped packets, or is it just that the capture mechanism cannot 
> report dropped packets on my OS but shows it as 0?

It means that "pcap_stats()" returned 0 as a count of dropped packets.

On OSes where the capture mechanism can report drops, it really means 
zero packets were dropped by the capture mechanism (it says nothing 
about cards dropped by the network interface, for example).

On OSes where it can't, it means nothing.

I have a partially-implemented new API for libpcap, in which the 
statistics are returned with bitflags indicating which statistics are 
being supplied.  It allows new statistics to be added *and* allows 
statistics *not* to be reported; if I get a chance to finish it in 
time, it'll be in a future libpcap release, and will allow platforms 
where you can't get a count of dropped packets not to report that 
statistic at all, in which case a future release of Ethereal, when 
built on a system with that API and running on such a system, wouldn't 
say how many packets were dropped.  (I have no timeframe for when this 
will be done, and can't give one.)