单项选择题
A.Addresses are permanently assigned so that the host uses the same address at all times.
B.Addresses are assigned for a fixed period of time. At the end of the period, a new request for an address must be made, and another address is then assigned.
C.Addresses are leased to hosts. A host will usually keep the same address by periodically contacting the DHCP server to renew the lease.
D.Addresses are allocated after a negotiation between the server and the host to determine the length of the agreement.
单项选择题 A network engineer wants to allow a temporary entry for a remote user with a specific usename and password so that the user can access the entire network over the internet.which ACL can be used?（）
单项选择题 On which options are standard access lists based?（）
多项选择题 What are two benefits of using NAT?（）