Re: RFC 3484 Section 6 Rule 9

Well, longest prefix match is kind of useful in some scenarios i think.

Imagine a site that is multihomed to two ISPs and has two PA address blocks.

Now, longest prefix match ensures that when a node of the multihomed 
site wants to contact any other customer of its own isps, it does 
perform the correct source address selection and that is likely to be 
critical for the communication to work, especially if the isps are doing 
ingress filtering (i am assuming that the intra site routing of the 
multihomed site will preffer the route through the ISP that owns the 
prefix contained in the destiantion address)

Even though this is one case and the problem is more general, i tend to 
think that this is an importnat case and things would break more if this 
rule didn't exist

Regards, marcelo

Mark Andrews escribió:
> 	This rule should not exist for IPv4 or IPv6.  Longest match
> 	does not make a good sorting critera for destination address
> 	selection.  In fact it has the opposite effect by concentrating
> 	traffic on particular address rather than spreading load.
>
> 	I received a request today asking us to break up DNS RRsets
> 	as a workaround to the rule.    Can we please get a errata
> 	entry for RFC 3484 stating that this rule needs to be ignored.
>
> 	Mark
>   

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