nanog mailing list archives

Re: Updated prefix filtering


From: Mark Andrews <marka () isc org>
Date: Mon, 11 May 2015 09:17:05 +1000


In message <CAA93jw7NrW7D7YOM7gWj+2up3xPFZdv5u=9c3cTdm+wtaGTB6Q () mail gmail com>
, Dave Taht writes:
On Fri, May 8, 2015 at 3:41 PM, Chaim Rieger <chaim.rieger () gmail com> wrote=
:

Best example  I=E2=80=99ve found is located at http://jonsblog.lewis.org/=
 <http://jonsblog.lewis.org/>

I too ran out of space, Brocade, not Cisco though, and am looking to filt=
er prefixes. did anybody do a more recent or updated filter list  since 200=
8 ?

Offlist is fine.

Oh and happy friday to all.

I have had a piece long on the spike on how we implemented bcp38 for
linux (openwrt) devices using the ipset facility.

We had a different use case (preventing all possible internal rfc1918
network addresses from escaping, while still allowing punching through
one layer of nat ), but the underlying ipset facility was easily
extendible to actually do bcp38 and fast to use, so that is what we
ended up calling the openwrt package. Please contact me offlist if you
would like a peek at that piece, because the article had some
structural problems and we never got around to finishing/publishing
it, and I would like to....

has there been a bcp38 equivalent published for ipv6?

Yes, BCP 38.  BCP 38 is address family agnostic.  Just because the
examples use IPv4 addresses doesn't mean that the concepts don't
just map straight over onto IPv6.

Source based routing is really only needed because BCP 38 filtering
is being poorly implemented.  Rather than collecting the full set
of legitimate source addresses ISP's are only accepting the set of
source addresses that they have allocated to the customer.

With SIDR it should be possible to pass certs to the other ISP's
that say "I am a legitimate source of these addresses" and do this
all automatically.

Along the way source specific routing showed up for ipv6 and we ended
up obsoleting the concept of an ipv6 global default route entirely on
a linux based CPE router.

see: http://arxiv.org/pdf/1403.0445.pdf and some relevant homenet wg stuff.

d@nuc-client:~/babeld-1.6.0 $ ip -6 route

default from 2001:558:6045:e9:251a:738a:ac86:eaf6 via
fe80::28c6:8eff:febb:9ff0 dev eth0  proto babel  metric 1024
default from 2601:9:4e00:4cb0::/60 via fe80::28c6:8eff:febb:9ff0 dev
eth0  proto babel  metric 1024
default from fde5:dfb9:df90:fff0::/60 via fe80::225:90ff:fef4:a5c5 dev
eth0  proto babel  metric 1024

So this box will not forward any ipv6 not in the from(src) table.

--=20
Dave T=C3=A4ht
https://plus.google.com/u/0/explore/makewififast
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka () isc org


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