> Sander, > > I think that what you are saying is true. Do folks agree? >
agree, yes. But at the same time I should point out that this approach has some serious downside risk. This limited advertisement scope was the theory behind the intended routing scope of 2002::/16. The theory was that every provider would advertise 2002::/16 to its customers, and noone would need to take the unfunded transit traffic hit of advertising this gateway prefix globally. And some providers did precisely that. However most folk did absolutely nothing, so reachability into the 2002::/16 space was erratic, unmanaged and non-functional. The approach described below by Sander could be seen as a replay of this same piecemeal limited scope advertisement scenario, and has the same risk. What's the risk? Again 2002::/16 has some clues. While the experiment is of small scale and the traffic levels are insignificant some folk will advertise the /32 prefix globally and absorb the unfunded transit traffic as part of the experiment. This sounds great, but it has some serious downsides. The consequent routing from the non-LISP world to the LISP world may well have highly inefficient and lengthy paths for many, as the "closest" gateway may well be on the other side of the planet. (e.g. from Australia I still send most of my Teredo traffic via Amsterdam - obviously performance sucks when this happens!) The consequent impact on performance of these extended "dog leg" paths that need to head to the PITR gateway to transit between the LISP and non-LISP routing domains which may well have some negative impact on the perceptions of LISP performance in the context of this experiment. i.e. it appears that the negative 6to4 perceptions were not only due to widespread use of local protocol 41 filters, but also due to the asymmetric and highly erratic transit paths between end users and the sparsely deployed 6to4 gateways. Geoff On 6 Dec 2013, at 3:06 am, Ronald Bonica <[email protected]> wrote: > > >> -----Original Message----- >> From: Sander Steffann [mailto:[email protected]] >> Sent: Thursday, December 05, 2013 2:02 AM >> To: Dino Farinacci >> Cc: Ronald Bonica; Luigi Iannone; Geoff Huston; LISP mailing list list >> Subject: Re: [lisp] WGLC draft-ietf-lisp-eid-block-07 >> >> Hi, >> >>> As I said before, the /32 advertisements of an EID-block are >> advertised within an ISP towards the edges of the network. Those edges >> are towards its customers so its customers, as sources in non-LISP >> sites, can reach destinations in LISP sites. >> >> So if it is only done this way, that means for global reachability of >> the LISP prefix at least one global transit provider has to run PITRs. >> They wouldn't mind attracting the traffic from their customers. That is >> what they are paid for :-) That would make it work, *if* we can >> convince the big transit(s). >> >> Cheers, >> Sander >> >> > > _______________________________________________ lisp mailing list [email protected] https://www.ietf.org/mailman/listinfo/lisp
