Re: performance of libnet-based tools

On Fri, 25 Feb 2005, Steven Alexander Jr. wrote:
> Failed to send packet: No buffer space available

BPF_MAXBUFSIZE controls this value and lives in
sys/net/bpf.h (usually installed under /usr/src).

you can see the current buffer size with the following command.

sysctl -a |grep bpf

You'll have to rebuild, reinstall your kernel after any change to this 
amount.

You might need to increase your maxusers tunable to avoid a panic when the 
kernel trys to allocate another buffer but not enough kernel memory is 
available.  See tuning(7) for more information.

You might try the freebsd -net or -performance mailing lists if you have
any more questions.

> The synflood tool that comes as a libnet sample works
> for several seconds and begins reporting:
>
> libnet_write: libnet_write_raw_ipv4(): -1 bytes
> written (Host is down)

I'll let somebody else answer this one.

All the best,

--
Mark Atkinson
(!wired)?(coffee++):(wired);