Subject: Re: [pim] null register dummy ip header

From: Nidhi Bhaskar <[email-masked]>
Date: Thu, 5 Jun 2003 12:35:38 -0700 (PDT)

> > And something similar with IPv6.
>
> Hmm, but IPv6 does not have a checksum field in its base header:
>
>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>    |Version| Traffic Class |           Flow Label                  |
>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>    |         Payload Length        |  Next Header  |   Hop Limit   |
>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>    |                                                               |
>    +                                                               +
>    |                                                               |
>    +                         Source Address                        +
>    |                                                               |
>    +                                                               +
>    |                                                               |
>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>    |                                                               |
>    +                                                               +
>    |                                                               |
>    +                      Destination Address                      +
>    |                                                               |
>    +                                                               +
>    |                                                               |
>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> (from Section 3 of RFC 2460)
>
> So, if we really need to care about this for IPv6, we may have to
> either:
>
> - add a (dummy) PIM header after the inner IPv6 header, and put the
>   checksum for the inner headers there.

Or specify that for IPv6 NULL registers the checksum calculation for
the outer PIM header SHOULD include the dummy IP header.
Implementations MUST accept NULL registers whose checksum does
not include the inner header.

However, this will mean adding configuration knobs when DRs are
updated before the domain's RP.

Thanks,
Nidhi.

>
> 					JINMEI, Tatuya
> 					Communication Platform Lab.
> 					Corporate R&D Center, Toshiba Corp.
> 					[email-masked]
> _______________________________________________
> pim mailing list
> [email-masked]
> http://catarina.usc.edu/mailman/listinfo/pim
>
_______________________________________________
pim mailing list
[email-masked]
http://catarina.usc.edu/mailman/listinfo/pim