In IPv4, subnets are generally small, made just large enough to cover
the actual number of machines on the subnet. In contrast, the
default IPv6 subnet size is a /64, a number so large it covers
trillions of addresses, the overwhelming number of which will be
unassigned. Consequently, simplistic implementations of Neighbor
Discovery can be vulnerable to deliberate or accidental denial of
service, whereby they attempt to perform address resolution for large
numbers of unassigned addresses. Such denial of attacks can be
launched intentionally (by an attacker), or result from legitimate
operational tools or accident conditions. As a result of these
vulnerabilities, new devices may not be able to "join" a network, it
may be impossible to establish new IPv6 flows, and existing IPv6
transported flows may be interrupted.
This document describes the potential for DOS in detail and suggests
possible implementation improvements as well as operational
mitigation techniques that can in some cases be used to protect
against or at least alleviate the impact of such attacks.
Working Group Summary
The topic was discussed in v6ops, with essentially smooth consensus supporting the document.
This is a problem statement. As such, one doesn't expect an implementation...
Fred Baker is shepherd.