单项选择题
A. Subnet strategy for private companies.
B. Manage and scale the growth of the internal network.
C. Conserve public IP addresses so that we do not run out of them.
D. Allow access reserved to the devices.
单项选择题 Which layer of the OSI reference model uses flow control, sequencing, and acknowledgements to ensure that reliable networking occurs?（）
单项选择题 Which layer of the OSI reference model uses the hardware address of a device to ensure message delivery to the proper host on a LAN?（）
单项选择题 Which option is a valid IPv6 address?（）