There will be many large-scale Internet threats that plague the IPv6 Internet in just the same way as DoS attacks disrupt today's Internet. Hopefully the larger address space of IPv6 will make scanning worms a thing of the past; however, other types of worms are likely to evolve. If service providers and customer organizations are performing ingress and egress filtering, tracebacks will be easier. The more research done on these IPv6 Internet threats, the more secure the IPv6 Internet will be in the future.
Service providers might be hesitant to add IPv6 functionality to their production IPv4 networks. They have a fear that new IPv6 vulnerabilities will lead to instability of their revenue-generating IPv4 networks. Network service providers can leverage secure BGP peering to help make the Internet a safer place for all. If service providers perform the proper filtering, they can mitigate many of these risks. Many organizations are connecting to dual-stack services today, and service providers can leverage their existing MPLS infrastructures to create secure IPv6 services.
The key is to make the customers' experience transparent, which means making it easy for them to configure their devices and securely automate address assignments. However, customers will have the same demands of IPv6 Internet connectivity as they have with IPv4 Internet connectivity. That means that solutions to IPv6 multihoming will need to be developed and secured.