[Winpcap-users] pcap_open_offline returns "bad dump file format".

[Guy Harris]

Narayanasamy, Raja M wrote:

>      I wrote a simple application using the WinPcap developer pack 4.0 
> API. The application uses pcap_open_offline() API call  to open the 
> .pcap file and subsequently it uses other pcap API to collect all packet 
> details.  My application works fine with all .pcap files captured using 
> ethereal.
> 
> But when I run my application with .pcap file captured using NetOptics 
> hardware sniffer,  the pcap_open_offline() API fails with an error text 
> saying “bad dump file format”.
> 
> Ethereal software can successfully open the same .pcap file my 
> application fails to open.

Read the file in with Ethereal and then select "Summary" from the 
"Statistics" menu.

What does it say for "Format" in the summary dialog that opens?