4.9-STABLE heavily dropping packets? libpcap issue?

[Emre Bastuz]

Hi,

for sniffing purposes I have a FreeBSD 4.9-STABLE box running on highend,
state-of-the-art hardware (Xeon something) with all bells and whistles.

The NIC´s an onboard copper em0 with gig-e capabilities.

Nevertheless I am getting massive packet drops (40%-60%) when I start sniffing a
gigabit ehthernet segment although the CPU load is very low.

After doing some research in in the appropriate mailing list archives I found
out that there are (or were?) sometimes issues with the libpcap. As there was a
more current one in the ports collection (0.8.1 as opposed to 0.7 in the base
system) I used this instead (with LIBPCAP_OVERWRITE_BASE=yes) but still I am
losing the same amount of packets when doing a tcpdump.

I definitly do _not_ know what else I can do to reduce the amount of lost data.
*sigh*

Things I did to improve the situation so far:

- Update from RELEASE to 4.9-STABLE
- Compile a custom kernel with reduced drivers and SMP support
- Update libpcap and recompile tcpdump

Does any of you have an idea else I can do?

Any parameters in the kernel that can be tweeked further, like NMBCLUSTERS or
NMBUFS?

Cheers,

Emre

--
http://www.emre.de                        UIN: 561260
PGP Key ID: 0xAFAC77FD

I don't see why some people even HAVE cars. -- Calvin

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.