IPv6 PI allocation
Niels Bakker
niels=cluenet at bakker.net
Thu May 17 19:52:40 CEST 2007
>>>> RFC3178-style multihoming will create more entries in the global
>>>> routing table once a network using that connects to an IXP.
>>>not at all. RFC3178 does not require ISPs to announce any specific
>>>routes (other than /29 or /32 of the ISP).
>> RFC3178 exists in some kind of fantasy world. Quoting from it, "3.
>> Basic mechanism": "We assume that our site is connected to 2 ISPs, ISP-A
>> and ISP-B."
>>
>> This is an unrealistic requirement for the reasons I spelled out (the
>> need to connect to an IXP,
>no need to connect to any of IXes (by IXP you mean Internet eXchange
>Points - am I right?).
No need? No possibility, you mean. The need exists on the current
Internet (in both technical and business climate), why do you think that
would disappear?
(What else could I mean with IXP in the context of multihoming?)
>> plus the need for independence from any ISP's
>> network
>this is not fullfilled by RFC3178, that's true. see below.
>> - you cannot withdraw an announcement from a particular broken
>> upstream except by pulling all DNS records).
>you can workaround this with RFC3178. the assumption is that ISP-A
No you cannot. If ISP-B disappears (and with that I mean their
/29-to-/32 disappears from the global routing table) half the session
setups to hosts within the RFC3178-multihomed site will time out.
>and ISP-B are having transit relationship with each other, that's all.
That would rule out end sites connecting directly to two tier-1s.
I remain convinced that RFC3178 describes a technically sound solution
that is acceptable to a very small minority of sites looking to
multihome.
-- Niels.
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