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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: And Now for Something Completely Different (was Re: IPv6 news)
Forgot to subscribe to nanog-post first time round... -------- Forwarded Message -------- On Sun, 2005-10-16 at 05:31 -0400, Joe Maimon wrote: > Long story short, seperating endpoint/locator does nothing to allow > multiple paths to a single IP6 address/prefix to scale. I may be wrong - I haven't been following shim6 for long, but to me it does appear to scale because it is moving the host identity problem from being an IP address that exists in a single long prefix in the core routing table to being an identifier (128 bit number) which maps to a number of existing IP addresses which each already live in much shorter prefixes in the core routing tables. i.e. move the problem from the core to the edge nodes. Those edge node only need to locator lookup tables for the hosts they are talking to - not all that they may talk to. e.g. Say there is a host a::1 and my server has 3 IP addresses b::1, c::1 and d::1, via service providers B, C and D. As it stands, obviously a::1 can talk directly to the server using any of the addresses. Now, say I want to multi-home. Obviously in the past, I would have gotten my own prefix, say e:: and ASN and announced it. But now with shim6, I could use e::1 as the identifier for my host and use b::1, c::1 and d::1 as the locators. So now someone requests a AAAA for my host and gets back e::1. Now when a::1 tries to connect to e::1, the shim does a lookup and sees three possible locators - b::1, c::1 and d::1. It selects one of them and packets are then routed between a::1 and one of b::1, c::1 and d::1 in the same way that they would today. How are there traffic engineering problems when at the end of the day the packets will still be routed in the same way? Or am I missing some crucial point? Regards, John
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