nanog mailing list archives

Re: Time to add 2002::/16 to bogon filters?


From: j k <jsklein () gmail com>
Date: Mon, 18 Jun 2018 21:32:51 -0400

This week I began mapping IPv6 SPAM headers "Received:" and "X-Received:"
and have discovered over 50% are from:

10.0.0.0 – 10.255.255.255
2002:0a00:: - 2002:aff:ffff:ffff:ffff:ffff:ffff:ffff

172.16.0.0 – 172.31.255.255
2002:ac10:: - 2002:ac10:ffff:ffff:ffff:ffff:ffff:ffff

192.168.0.0 – 192.168.255.255
2002:c0A8:: - 2002:c0A8:ffff:ffff:ffff:ffff:ffff:ffff

Can anyone else confirm my findings?

Joe Klein

"inveniet viam, aut faciet" --- Seneca's Hercules Furens (Act II, Scene 1)
PGP Fingerprint: 295E 2691 F377 C87D 2841 00C1 4174 FEDF 8ECF 0CC8

On Mon, Jun 18, 2018 at 9:18 PM, Jared Mauch <jared () puck nether net> wrote:



On Jun 18, 2018, at 8:31 PM, Mark Andrews <marka () isc org> wrote:

If you are using 2002::/16 you know are relying on third parties.  Not
that it is much
different to any other address where you are relying on third parties.

If one is going to filter 2002::/16 from BGP then install your own
gateway to preserve
the functionality.

It does not appear the functionality is working at present, which I think
is the more critical point.  Taking a quick sampling of where I see the
packets going from two different networks, it doesn’t seem to be going
where it’s expected, nor is it working as expected.  These appear to be at
best routing leaks similar to leaking rfc6761 space that should be under
your local control.  They could also be seen as a privacy issue by taking
packets destined to 2002::/16 somewhere unexpected and off-continent.

I would expect even in the cases where it does work, it would be subject
to the same challenges faced by people using VPN services (being blocked
from your kids favorite streaming services) and much poorer performance
than native IPv4.

There is also the problem noted by Wes George with 6to4 being used in DNS
amplification, which may be interesting..

http://iepg.org/2018-03-18-ietf101/wes.pdf

I don’t believe most providers are intending to offer 6to4 as a global
service.  Even the large providers (eg: Comcast) seem to have disabled it
~4+ years ago.  While I know there’s people on the internet that like to
hang on to legacy things, this is one that should end.  The networks and
devices today no longer require this sort of transition technology, and the
networks where it’s left won’t want it as it will be used for various bad
things(tm).

- Jared


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