ipfilter + bge strangeness

[Oleg Bulyzhin]

On Sat, Jan 28, 2006 at 11:16:31PM +0100, Koen Martens wrote:
> Oleg Bulyzhin wrote:
> > Could you please run 'tcpdump -nvi bge0' while you are generating
> > dns traffic (having bge0 checksum offloading on)?
> > 
> > 'netstat -sp udp' output might be helpful too.
> 
> Sure thing, although it happens with other kinds of traffic too (in
> the dump, there's some NTP for example). Here's the netstat output
> before:
> 
> http://www.metro.cx/bge/pre.txt
> 
> Here's the tcpdump output:
> 
> http://www.metro.cx/bge/tcpdump.txt
> 
> And netstat after..:
> 
> http://www.metro.cx/bge/post.txt
> 
> Seems like the bad checksums are on outgoing packets only, which
> sort of explains why with 5.4 there were no problems (as it only has
> the option rxcsum). txcsum and rxcsum are linked however, it is
> either both on or both off on 6-stable..
> 
> Thanks for your reply,
> 
> Koen

Btw, until recent changes bge had txcsum (not rxcsum) only.

As i can see there is no problem with checksum's at all (at least inside
bge driver). tcpdump reports bad checksum on outgoing packets due to
nature of tx checksum offloading: packet will get it's checksum calculated
right before it goes on wire (If you want to check tx checksum offloading
you should look on incoming packets on other end of wire).

Looks like something is wrong inside ipfilter. Can you test with ipfilter
turned off (ipf -D or, if you using module, kld_unload ipl.ko)?

> 
> 
> 
> -- 
> K.F.J. Martens, Sonologic, http://www.sonologic.nl/
> Networking, hosting, embedded systems, unix, artificial intelligence.
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-- 
Oleg.