Something with filters
Eric Vyncke (evyncke)
evyncke at cisco.com
Thu Aug 28 16:28:53 CEST 2014
The mapped IPv4 address is probably coming out of a 6PE (or 6VPE) MPLS router where the HopLimit field is copied into the MPLS header and when the poor P router in charge of sending the ICMPv6 has no IPv6 address at all… This is per RFC and perhaps an explanation why uRPF is not activated?
No explanation about the :: address though…
As a security person, I would love to have uRPF enabled where possible but I am afraid that even in IPv4 it is not deployed everywhere :-(
PS: indeed, ask your vendors for features, customers have much more power than you guess :-)
From: Lorenzo Colitti <lorenzo at google.com<mailto:lorenzo at google.com>>
Date: jeudi 28 août 2014 07:46
To: Jeroen Massar <jeroen at massar.ch<mailto:jeroen at massar.ch>>
Cc: IPv6 Ops list <ipv6-ops at lists.cluenet.de<mailto:ipv6-ops at lists.cluenet.de>>
Subject: Re: Something with filters
On Wed, Aug 27, 2014 at 9:01 AM, Jeroen Massar <jeroen at massar.ch<mailto:jeroen at massar.ch>> wrote:
9 2001:5a0:a00::2e (2001:5a0:a00::2e) 79.018 ms 79.910 ms 79.960 ms
10 :: (::) 101.893 ms 102.004 ms 103.574 ms
11 rar3.chicago-il.us.xo.net<http://rar3.chicago-il.us.xo.net> (::ffff:184.108.40.206) 104.732 ms
Yeah baby, we can use the unspecified address in ICMP replies!
The mapped IPv4 address in there is pretty cool, too...
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