Re: Libpcap performance under VMWare guest OSes

["Mark Bednarczyk" <voytechs () yahoo com>]

The debian packages are:

ubuntu9-x86:~# dpkg-query --show libpcap0.8
libpcap0.8      1.0.0-1

ubuntu9-x86:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 9.04
Release:        9.04
Codename:       jaunty


deb5-x86:~# dpkg-query --show libpcap0.8
libpcap0.8      0.9.8-5

deb5-x86:~# lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 5.0 (lenny)
Release:        5.0
Codename:       lenny

Cheers,
mark...

> -----Original Message-----
> From: tcpdump-workers-owner () lists tcpdump org
> [mailto:tcpdump-workers-owner () lists tcpdump org] On Behalf Of
> Guy Harris
> Sent: Thursday, December 10, 2009 8:16 PM
> To: tcpdump-workers () lists tcpdump org
> Subject: Re: [tcpdump-workers] Libpcap performance under
> VMWare guest OSes
>
>
> On Dec 10, 2009, at 4:45 PM, Mark Bednarczyk wrote:
>
> > Somehow libpcap, when it taps into this captured traffic,
> is not able
> > to handle a fraction of the actual traffic.
>
> The code path through libpcap shouldn't change merely because
> you're running in a VM - it should be the exact same, as long
> as the Ubuntu host and guest are using the same version of libpcap.
>
> You say "libpcap 0.8" - does that mean that version of
> libpcap whose tcpdump.org version number is 0.8.x, or does it
> mean the package that the Debian people (and thus, I think,
> the Ubuntu people) call "libpcap0.8" regardless of the
> tcpdump.org version number?  In the stable version, it's
> actually libpcap 0.9.5:
>
>
> http://packages.debian.org/search?keywords=libpcap&searchon=na
> mes&suite=stable&section=all
>
> I.e., what does "tcpdump -h" print?  That'll give you the
> tcpdump.org version numbers of libpcap and tcpdump.  Does it
> print the same numbers on the Ubuntu host and guest OSes?
>
> However, even if they're running the same version of libpcap,
> the code path up *to* libpcap could change.  Are they using
> the same drivers for eth2 on the host and guest machines?
> And are they running the same version of the kernel?
>
> (I'm assuming the machine running Windows XP as the host with
> Ubuntu as a guest has equal or greater capabilities - CPU,
> memory, etc. - than those of the machine running Ubuntu as
> the host, and that the set of processes running on the Ubuntu
> guest are about the same as those running on the Ubuntu host,
> so that it's not that the Ubuntu guest is working harder at
> other things, and that there's nothing else significant
> running on the Windows XP host at the time you're doing this,
> so that it's not that the host isn't giving most of the
> CPU/memory/etc. to the guest.  It also sounds as if your test
> application is not doing anything with the packets other than
> counting them, so it's not as if it's dropping packets
> because it can't process them quickly enough or write them
> quickly enough to a file.)- This is the tcpdump-workers list.
> Visit https://cod.sandelman.ca/ to unsubscribe.


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