单项选择题
A.It monitors messages from the external server and updates the routing table as needed.
B.It maintains the leases for the DHCP server and reassigns addresses to new subscribers.
C.It sends keep alives to the subscriber and makes the address available when the subscriber stops responding.
D.It sends keep alives to the subscriber and removes the host route when the subscriber stops responding.
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？（）
单项选择题 You would like to configure an ATM PVC with a virtual circuit identifier of 33 on virtual path 0.The PVC should use an unspecified bit rate and be encapsulated in the AAL5SNAP format.Which command accomplishes this goal？（）