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List:       quagga-users
Subject:    [quagga-users 11838] Re: OSPFv3 redistribution issues [Solved]
From:       Alexis Rosen <quagga-users () alexis ! users ! panix ! com>
Date:       2010-09-25 4:21:45
Message-ID: 8ADE7B37-4500-4329-B63A-C7ED74194A1C () alexis ! users ! panix ! com
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On Sep 24, 2010, at 6:04 AM, Ruben Laban wrote:
> Linux turns out to have an "odd" algorithm to determine the link 
> local address of a sit interface. Instead of the usual eui-64 based-on-mac-
> address link local address, it adds one based on the local ipv4 endpoint. That 
> in itself isn't that much of a problem. The problem is that it gets added with 
> a /128 prefix length! This obviously results in the 2 link local addresses on 
> either end of the link to not being able to reach each other.

This vaguely rings a bell - I'm sure you can find an RFC on this if you look. But I \
agree that it's rather useless. Either a host route for the far-end /128 should be \
generated automatically when the tunnel comes up, or (my preference) a proper /64 \
link-local network should be established.

If there's no RFC this might be a Linux bug...

On Sep 24, 2010, at 11:31 AM, Lennart Sorensen wrote:
> Doesn't doing that defeat the purpose of 'link local' addresses?

No, becuase...
> After all they are explicitly NOT to be routed.

...that's not relevant.

> If you want IPv6 addresses you can route and use outside of one physical
> network link, then assign them yourself properly.  The link local address
> is there (as far as I understand it) for network management of the link,
> not for actually passing any traffic.

Just because you can't route LL addresses, doesn't mean you can't pass traffic using \
them, FSVO of "using". In fact, it's quite common for hosts to route default through \
the LL address of their v6 router. Note that they don't use their LL address as the \
packet source when they do that. In other words, you can't use LLs as a source \
address, but you can use them as route targets.

/a
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