Technical Summary
The functionality provided by IPv6's Type 0 Routing Header can be
exploited in order to achieve traffic amplification over a remote
path for the purposes of generating denial-of-service traffic. This
document updates the IPv6 specification to deprecate the use of IPv6
Type 0 Routing Headers, in light of this security concern.
Working Group Summary
This document is a product of the IPv6 WG. Considerable
discussion of the impacts of the Type 0 processing
has happened over the course of the last few months.
The document, as it currently stands, has the backing
of the (rough) consensus of the group. However, the
topic has generated a lot heated discussion, and this
action is not unanimously supported by everyone in the
group. Counter arguments against deprecation have
raised potential (but so far unused) applications,
difficulty of introducing new similar functionality
once the feature has been disabled, ability to
deal with this issue in an operational manner,
the difference to the IPv4 situation (where source
routing is still a part of the specifications), etc.
The authors, chairs, and the AD believe, however, that
the current contents of the document have the backing
of the majority of the group, and that the recommendation
is a valid one. In particular, new RH types can and
have been defined for more specialized uses safely,
and it would be hard to depend on RH0 in new applications,
given that it has legitimate security issues and
that irrespective of IETF's documents, this feature
is largely disabled in many IPv6 implementations.
Protocol Quality
Jari Arkko has reviewed this document for the IESG. Several
implementations of IPv6 have for a long time not allowed
Type 0 Routing Header processing by default; recently
a number of implementations (BSD, for instance) have
disabled it in accordance with this document's
recommendations.
Call for input also in NANOG list was made.
Note to RFC Editor
Please change:
OLD:
IPv6 nodes MUST NOT process RH0 in packets whose
destination address in the IPv6 header is an address assigned to them.
Such packets...
NEW:
An IPv6 node that receives a packet with a
destination address assigned to it and containing an RH0 extension
header MUST NOT execute the algorithm specified in the latter part
of Section 4.4 of [RFC2460] for RH0. Instead such packets...
OLD:
type-2 RH
NEW:
type 2 Routing Header