Re: Have I misunderstood an ipchains concept?
Quoting Christian Pernegger (pernegger@chello.at):
> >
> > Volume 1 of Rich Stevens' TCP/IP Illustrated indicates that your thinking
> > is correct. It's in section 2.7, where the book discusses the loopback
> > interface. I'll quote from the book for bit here:
> > ---
> > Datagrams sent to a broadcast address or a multicast addresss are copied
> > to the loopback interface and sent out on the Ethernet. This is because
> > the definition of broadcasting and multicasting includes the sending host.
> > ---
>
> Maybe the keyterm here is copied? Then the vroadcasting host'd get 2 packets
> ... hmmm.
No. The outgoing packet is copied to the loopback interface which
makes it turn up as input. That's the only packet the sending host
should see.
The packet that is broadcast on the ethernet should not be received by
the NIC. It should pass along the wire past all the other interfaces and
be absorbed by the termination at each end of the cable.
If by any chance it *is* received because of faults elsewhere, it gets
dropped in net/ipv4/route.c .
Cheers,
--
Email: d.wright@open.ac.uk Tel: +44 1908 653 739 Fax: +44 1908 655 151
Snail: David Wright, Earth Science Dept., Milton Keynes, England, MK7 6AA
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official stationery. Views expressed here are either my own or plagiarised.
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