多项选择题
A.It burns IP addresses.
B.It conserves IP addresses.
C.A group of PVCs is a subnet.
D.It provides an umbered IP address to the ERX
E.It provides an IP unnumbered address to ERX
单项选择题 How does the ERX Edge Router interact with subscriber IP addresses assigned by an external DHCP server?（）
单项选择题 Which configuration command allows the ERX Edge Router to advertise customer networks into the provider’s IGP？（）
多项选择题 Which two B-RAS service offerings maintain the analog dial-up model with centralized user authentication，authorization，andaccounting？（）