单项选择题 The following configuration line was added to router R1 Access-list 101 permit ip 10.25.30.00.0.0.255 any What is the effect of this access list configuration？（）

单项选择题 GivenanIPaddress172.16.28.252withasubnetmaskof255.255.240.0，whatisthecorrectnetworkaddres？（）

单项选择题 What is the name of the VTP mode of operation that enables a switch to forward only VTPadvertisements while still permitting the editing of local VLAN information?（）