outer using a source address that was not advertised by that router? Ingress filtering is a common practice in leaf networks, which would cause the traffic to be dropped (with a possible ICMPv6 sent back to the UE). If ingress filtering is not in place, the return traffic would anyway be routed towards the network where the source address topologically belongs, causing asymmetric routing to take place. Asymmetric routing is known to be problematic when it comes to stateful middle-boxes such as firewalls. We believe that the evolved bearer is a promising technology for localized content distribution and direct mobile-to-mobile communication. The evolved bearer is not only about breakout to the Internet. The breakout can definitely be into localized caches and information resources. Depending on the network architecture and the collocation prop- erties of the SGW and the PGW, the content can be distributed at multiple levels in the access network. Handovers Only the PGW anchored prefix provides mobility. When either the eNodeB or the SGW changes as a result of a handover, there is no guarantee that the target eNodeB or SGW is in the same topological area. Therefore, the UE should always verify whether the Deploying IPv6 in 3GPP Networks old IP configuration on its multi-address interface is still valid after a handover [20]. It is expected that a UE that implements the evolved bearer also implements the simple procedure for Detecting Network Attachment DNA [21] in its IP stack and is able to provide the required link events to the IP stack from its network interface layer. Using DNA the UE can verify whether its evolved bearer IP configuration is still valid and renew the configuration when that is not the case. From the network point of view, both eNodeB and SGW routers must send Router Advertisements when a new mobile attaches to them. Another interesting case is the inter-technology handover. Existing 3GPP specifications already have a job lot of text spent for this subject. The evolved bearer does not even try 