Re: [long] "bad cksum 0!" on AIX 5 over loopback

[Shaun <delius () progsoc uts edu au>]

On Wed, 2 Jul 2003, alex medvedev wrote:

Hi Alex,

> questions:
> - what can be done about fixing the cksums?

Not sure on that one

> - why does pcap_read() receive EFAULT while reading from bpf?

That one is a mystery, it appears to be some sort of kernel issue with
uiomove(), I tried to determine what was going on, but gave up when I
found that memset()ing the buffer to 0 before using it made the problem go
away.

>   is it fixable?

Yes, don't use 0.7.2, use the latest.

>   do i miss any packets when doing "goto again" when receiving EFAULT?

Yes.

You should also note that the AIX bpf driver is buggy and may CRASH YOUR
MACHINE, do not use it in production. IBM have recently fixed the problems
and tell me a new version should be released around half way through
August.

Cheers,
Shaun

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