The NETLMM WG standardized Proxy Mobile IPv6 (PMIPv6). PMIPv6 enables mobile devices to connect to a PMIPv6 domain and roam across gateways without changing the IP address. Current PMIPv6 specification does only support the movement of hosts within the localized mobility domain. A mobile network (commonly referred to as a NEMO, NEtwork that MOves) can also benefit from the network-based localized mobility support provided by PMIPv6 [I-D.ietf-netext-pd-pmip], but with some limitations. This I-D describes what can be done with current standardized protocols, and describes the problem statement of fully supporting network mobility in Proxy Mobile IPv6.