While troubleshooting a network problem,a technician discovers that the current copy of the Cisco IOS is outdated and needs to be updated.Which of the following commands would the technician issue to replace the Cisco router IOS with the newer version?（）

How are VTP advertisements delivered to switches across the network?（）

What is the purpose of the cisco Vlan Trunking protocol?（）

At which layer of the OSI model is RSTP used to prevent loops?（）

You have been asked to come up with a subnet mask that will allow all three web servers to be on the same network while providing the max number of subnets.Which network address and subnet mask meet this requirement?（）

On which options are standard access list based?（）

Three switches are connected to one anther via trunk ports.Assuming the default switch configuration,which switch is elected as the root bridge for the spanning-tree instance of vlan 1?（）

Which device might be installed at a branch office to enable and manage an IPsec site-to-site VPN?（）

Which command is used to display the collection of OSPF link states?（）

After the show ip route command has been entered,the follwing routes are displayed.Which route will not be entered into the routing table of a neighboring router?（）