CCNP Routing and Switching ROUTE 300-101 Official Cert Guide

IPv6 Internet Connection Security

Connecting an enterprise network to the Internet through IPv6 introduces some security risks. A couple of examples are as follows:

The Neighbor Discovery process used by IPv6 might be leveraged by a malicious user to launch a man-in-the-middle attack, similar to a gratuitous ARP attack in an IPv4 network.

If an IPv4 network used NAT, the inside local addresses assigned to network devices would not be visible to devices on the Internet, because of NAT’s translation of inside local addresses to inside global addresses. ...