[6bone] why there is no checksum in IPv6 header?

[Janos Mohacsi]

On Wed, 20 Nov 2002, navaneetham wrote:

> Hi,
>
> 	what is the reason IPv6 doesn't have checksum in it's header? if header
> corrupted how this situation will handle by IPv6 router?

What is the reason to get the IPv6 packet get corrupted?

1. Usually It can happened in the lower layer, where much better error
detection and even correction mechanisms exist to prevent such a
corruption.

2. If some accidental thing happen to get IPv6 packet corrupted, then the
upper layer should handle the problem. With IPv6, the checksum is
mandatory for TCP (of course) and UDP (it was not the case for IPv4, to
speed up e.g. the NFS).

3. If somebody sending corrupted IPv6 packets, then the end system should
detect and drop it. However it might have some negative impact on the
performance of the end system receiving deliberately corrupted IPv6
packets. New form of DoS?

It was a engineering decision to off-load the routers from recomputing the
IP checksum everytime they forward a packet.

Best Regards,
		Janos Mohacsi
>
>
> Thanks,
> Navaneetham
>
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