RING measurements don't match access-networks (Was: Some very nice broken IPv6 networks...)
job at instituut.net
Mon Nov 10 11:48:49 CET 2014
On Mon, Nov 10, 2014 at 08:46:50AM +0100, Jeroen Massar wrote:
> > Some hosts are behind exotic 6to4 NATted tunnels,
> I am a bit surprised by such a statement, or the need for it
Because that's what it looks like? I don't know what else i'd call this:
job at amazon01:~$ ifconfig tun6to4
tun6to4 Link encap:IPv6-in-IPv4
inet6 addr: 2406:da00:ff00::1715:b057/128 Scope:Global
inet6 addr: ::10.28.34.28/128 Scope:Compat
> Also making a claim like that they are 6to4 that is known to be false,
> is a bit weird as there is no 2002::/16 address in the participants
All I wanted to point out is that there is a large diversity in how RING
nodes' IPv6 connectivity is arranged. I'll rephrase it as "Some hosts
are behind exotic setups".
> Actually, what that demonstrates is that out of a set of well-managed
> nodes, there are issues with PMTU. Hence, please contact these
> networks (they are part of the ring, thus that should be easy) and
> make them behave properly. That solves another set of problems.
Do you want to help engage with these networks?
> You might want to run a similar one from all the nodes, thus making a
> cross-RING MTU determination to get even better results, as I did it
> only from one vantage point. Maybe time for ring-mtu? :)
That sounds like a great idea, maybe it can be added to RING SQA as a
secondary type of alert? "MTU suddenly decreased or increased towards a
significant set of RING nodes"? https://github.com/NLNOG/ring-sqa
> > For NLNOG RING applications we mandate that there is 1 globally unique
> > IPv6 address on the host, we do not specify how this should be
> > accomplished. This leads to some variety, not all of those
> > implementations I would describe as "well behaved".
> While that is absolutely true, most of those boxes ARE well behaved, as
> the providers involved will take sure that there are no problems.
> And they definitely are not located in an access network on a dingy home
> DSL line...
I've asked some incumbents to provide this, but so far no dice. Thanks
for taking a deep dive. Randy Bush presented at RIPE69 comparing the
RING with RIPE Atlas, I thought it interesting:
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