> While I am at it I would like to try and seek acceptance for a new file
> format.

There have also been discussions on [EMAIL PROTECTED] about a
new file format; I'd prefer to try to solve as many problems as possible
with one new file format, so I don't want to add new capture file
formats too quickly.

Some goals I see for a new capture file format:

        able to handle multiple packet encapsulation types in a single
        capture

        somehow records the names of the network interfaces, so that in
        a multiple-interface capture file the packets can be associated
        with the interface (people have asked for this on
        tcpdump-workers, as tcpdump 3.6[.x] can capture on the "any"
        device on Linux (as can Ethereal 0.8.15) - names, *not* just
        Linux-style indices, so that the capture file can be read on a
        machine other than the one on which the capture was made

        perhaps records packet loss, etc.  statistics in some fashion
        (snoop format does this, see RFC 1761, and Network Monitor does
        this, too, albeit in a somewhat gross fashion - the statistics
        look like fake Ethernet frames)

        records, with each packet, an indication of whether the packet
        was

                sent by this host

                unicast to this host

                broadcast

                multicast to an address this host accepts

                received promiscuously ("none of the above")

                was received for some unknown reason (as on platforms
                where the capture mechanism doesn't tell you the above)

        as both Linux and Digital UNIX supply at least some of that
        information (and I saw something suggesting that the LBL folks
        at least contemplated it as a good idea for BPF) - the
        indication should be in a form readable even on platforms
        *other* than the one on which it was captured

        perhaps copes with the fact that some FDDI interfaces and the
        drivers for same appear to supply MAC addresses in bit-reversed
        form to the packet capture mechanism, so that you can tell from
        the file what bit order was used

        perhaps allows packets, on platforms with memory-mapped capture
        devices (Linux 2.4 and later, perhaps some or all of the BSDs
        with some stuff somebody's working on, perhaps others - I wish
        I'd done the memory-mapped stream head stuff I was thinking
        about when I was at Sun, as you could have gotten that on SunOS
        4.x and 5.x and possibly other OSes), to be written directly
        from the memory-mapped area, for speed (this might mean multiple
        capture file formats for different platforms).

I also would want this capture file format to be readable by libpcap,
and to have tcpdump handle it, so that it could be used by more than
just programs that use Wiretap.

I'm CCing tcpdump-workers on this.
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