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

On which options are standard access list based?（）

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?（）

What is the result of issuing the frame-relay map ip 192.168.1.2 202 broadcast command?（）

Which IPsec security protocol should be used when confidentiality is required?（）

An administrator must assign static IP addresses to the servers in a network.For network 192.168.20.24/29, the router is assigned the first usable host address while the sales server is given the last usable host address. Which of the following should be entered into the IP propertied box for the sales server?（）

Which command encrypts all plaintext passwords?（）

An employee of ABC company has move to an office on a different floor. Although the administrator is able to telnet to all of the routers,the address of Switch F is needed in order to verify that the employee remains in the same VLAN.Which action could be used by the administrator to find the IP address of Switch F?（）

What is the default administrative distance of OSPF?（）

Which statement is true, as relates to classful or classless routing?（）