what is the difference between .cap and .pcap formats??
Thanks and Regards,
asked 16 Feb '11, 00:19
From my point of view ".cap" is the Network General Sniffer format while ".pcap" is the TCPDump/Wireshark format, although I guess that a lot of analyzers name their format ".cap". Main difference is in the headers of the file and frames, meaning that they contain different amounts of information about frames. They all have at least sizing and timing informations as well as the content of the captured frame (as much bytes as the frame slicing setting allowed).
The Network General .cap Format has additional info about channel numbers for example which the standard pcap format doesn't as far as I know (as long as you don't have optional PPI information headers).
answered 16 Feb '11, 01:06
This is an all too common misconception amongst MS OS users, that the file name extension defines the file format. In reality it only hints to it, for the sake of human users. In reality the file format has to be defined by external means, like a MIME type or a magic number in the file header.
Coming back to the original question: What is the difference between the file formats of files with the extension .cap vs. .pcap, that question is hard to answer definitively, as Jasper already mentioned. .cap could hint the a Network General Sniffer format file, but in reality, going with the defacto 3 character file extension on MS OS's, the libpcap format is most likely. The .pcap extension definitely hints in that direction.
answered 16 Feb '11, 01:50
Uh... my first inclination is to answer "a letter."
Note that when analyzing .pcap or .cap files, Wireshark displays the same information.
Maybe we need to know why you asked the question... just curious or is there a need to understand if there are potential differences in file contents and support...
Lordy I couldn't reference Network General stuff anymore... been too many years since I played with those Sniffers... (or the old LANalyzer... sniff, sniff...). He he.
answered 16 Feb '11, 11:23