Cisco ASR 5000 Series Administration Manual page 78

▀ How GGSN Works
Figure 18. IPv6 Stateless Address Autoconfiguration Flow
1. The MS uses the IPv6 interface identifier provided by the GGSN to create its IPv6 link-local unicast address.
Before the MS communicates with other hosts or mobile stations on the intranet/ISP, the MS must obtain an
IPv6 global or site-local unicast address.
2. After the GGSN sends a create PDP context response message to the SGSN, it starts sending router
advertisements periodically on the new MS-GGSN link established by the PDP context.
3. When creating a global or site-local unicast address, the MS may use the interface identifier received during the
PDP context activation or it generates a new interface identifier. There is no restriction on the value of the
interface identifier of the global or site-local unicast address, since the prefix is unique.
▄ Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide
GGSN Support in GPRS/UMTS Wireless Data Services
OL-22944-02