> >I'm running NetBSD 3.0 on Mac Mini. I noticed weird problem with gem 
> >ethernet interface. It seems that enabling hardware checksums for TCP 
> >and/or UDP breaks ipfilter. Outbound connections are timing out like this:
> ...
> >This occurs only when IP filter is enabled. I can reproduce it also when 
> >using tcp4csum-rx and udp4csum-rx.
> ...
> >This config is working very well when checksums are disabled. When 
> >checksums are enabled, connections are timing out.
> 
> I can duplicate this problem on 3.0/macppc on an iBook SE.  My results are
> identical to yours.  I'm far from an expert on this subject, but did a little
> searching out of curiousity.

> I am curious to see if this happens with other network cards with hardware
> checksum support (e.g. hme, ex), I may take a crack at checking them out.
> 
> You may also want to try pf and see if it has the same problem.  (Or perhaps
> I will.)
> 

I could not duplicate this problem with 3.0/i386 and a 3COM 3C905B (ex) card,
with hardware checksumming enabled.  So it appears to be gem-specific.  (Unless
it's an architecture-related problem.)

Dave