Poor performance with natd/ipfw and TSO enabled on bce(4) card and 8.1-PRERELEASE

[Aleksandr A Babaylov]

On Thu, Jul 01, 2010 at 04:54:47PM -0700, Pyun YongHyeon wrote:
> On Wed, Jun 30, 2010 at 07:00:53PM -0700, Garrett Cooper wrote:
> > Hi,
> >     Just an observation I made while transferring a file:
> > 
> > # time scp floppy.img somehost:
> > Password:
> > floppy.img                                    100% 1440KB  13.7KB/s   01:45
> > 
> > real	1m59.400s
> > user	0m0.031s
> > sys	0m0.028s
> > # sysctl net.inet.tcp.tso=0
> > net.inet.tcp.tso: 1 -> 0
> > # time scp floppy.img somehost:
> > floppy.img                                    100% 1440KB   1.4MB/s   00:00
> > 
> > real	0m0.712s
> > user	0m0.018s
> > sys	0m0.018s
> > 
> >     Going ISDN speeds transferring a 1.44MB file is sad when you have
> > a gigabit uplink :(... natd seems to be doing a LOT of spinning when
> > TSO is enabled (it's going up to 73% CPU on a dual-proc quad-core
> > machine).
> I would use pf(4) if I have to handle lots of NAT rules.
Or ipfw nat.
man ipfw | grep nat