cd4 seq=1 45 29.558793 2001:6e8:2100:100::30 2001:6e8:2100:198:6b:85ff:fec9:35c4 ICMPv6 Echo (ping) reply id=0x1cd4. seq=1 46 30.269244 2001:6e8:2100:198:6b:85ff:fec9:35c4 2001:6e8:2100:100::30 ICMPv6 Echo (ping) request id=0x1cd4 seq=2 47 30.558749 2001:6e8:2100:100::30 2001:6e8:2100:198:6b:85ff:fec9:35c4 ICMPv6 Echo (ping) reply id=0x1cd4 seq=2 48 42.898861 fe80::6b:85ff:fec9:35c4 ff02::1:ff00:1 ICMPv6 Multicast Listener Report 49 42.898895 ff02::1:ff00:1 ICMPv6 Neighbor Solicitation for fe80:11 50 44.790176 fe80::6b:85ff:fec9:35c4 ff02::1:ff00:1 ICMPv6 Multicast Listener Report 62 53.826088 fe80::6b:85ff:fec9:35c4 ff02:12 ICMPv6 Multicast Listener Done 63 55.194931 2001:6e8:2100:198:6b:85ff:fec9:35c ff02::1:ff00:1 ICMPv6 Neighbor Solicitation for fe80:11 from 02:6b 64 55.196033 fe80:11 2001:6e8:2100:198:6b:85ff:fec9:35c4 ICMPv6 Neighbor Advertisement fe80:11 (rtr. sol, OVI 55.196092 2001:6e8:2100:198:6b:85ff:fec9:1 2001:6e8:2100:100::30 ICMPv6 Echo (ping) request id=0x1cd9 seq=7 66 55.500575 2001:6e8:2100:100::30 2001:6e8:2100:198:6b:85ff:fec9:35c4 ICMPv6 Echo (ping) reply id=0x1cd9. seq=7 67 55.557011 2001:6e8:2100:198:6b:85ff:fec9:35c4 2001:6e8:2100:100::30 ICMPv6 Echo (ping) request id=0xlcd9 seq=8 Figure 4.32 Example of NDP failure on a 3G link due to a UE configuring duplicate addresses on its interface. Losing the Initial Router Advertisement It is also possible that initial Router Advertisements get lost when a PDN Connection gets activated. If the initial MAX_INITIAL_RTR_ADVERTISEMENTS are lost, the UE does not have a default router or IPv6 prefix configured, which leaves the UE in a state where it has no IPv6 connectivity [167]. There are deployed (old) GGSNs that send only one Router Advertisement. Furthermore, some GGSNs may or may not respond to a Router Solicitation. Losing a Router Advertisement on a 3GPP link should not happen. The persistent claim has been that no packet ever gets lost due to excessive retransmissions that are practiced over the 3GPP radio. In reality, Router Advertisements do 