ed source address available (see Section 3.5.1). 4. Prefer a Mobile IP HoA: a destination addresses is preferred for which a host would use an HoA as a source address. 5. Prefer matching label: a destination address is preferred for which a host has a source address with a matching label. 6. Prefer addresses with higher precedence: a destination address that has higher preference based on the default address selection policy table is preferred. Deploying IPv6 in 3GPP Networks 7. Prefer native transport: a destination address that does not require encapsulation or protocol translation is preferred. 8. Prefer smaller scope: a destination address with the lowest possible scope is preferred, for example, a link-local scoped address pair is preferred to a global scoped address pair. 9. Use longest matching prefix: prefer a destination address that has the longest matching prefix with available source addresses in order to prefer addresses closest to each other in the network topology. 10. Leave the original order - for example the order as received from the DNS - of the destination address list unchanged. On Sending Packets via Correct Network Interface The source address selection rule 5, about preferring source addresses from the network interface that will be used for sending a packet to a destination, has special importance in certain deployments. Namely, if a packet is sent over a different network interface than where the source address is configured, packet drops may occur. Firstly. a reply for the sent packet will arrive on the interface where the address is actually configured. This is called asymmetric routing. In the case of asymmetric routing, the network on the path of the reply packet has not seen the outgoing packets, and hence may, based on firewall ingress filtering policies, drop the packet as being 'unsolicited'. Secondly, a router on the network used for sending a packet may employ ingress filtering for the packets coming from hosts in the same network, as described in RFC 2827 (BCP 38) [94] and in