2004-10-01 16:21:39

by Rahul Jain

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Subject: Difference between Header Cache and Neighbour

Hi All,

I am not able to figure out what is the difference between the Header
Cache and the Neighbour structure.

The function I am looking into is ip_finish_output2() (ip_output.c). In
that function the kernel is checking whether the dst_entry for a skb
contains 'hh' or 'neighbour'. It then calls the output function of one of
them.

What I am confused about is that, when going through the code, I found
that hh->output and neighbour->output, both point to dev_queue_xmit. Is
this correct ? And if so, then what is the difference between dst->hh and
dst->neighbour.

I would appreciate your advice and comments

Thanks,
Rahul.