The network administrator cannot to switch 1 over a telnet session,although the hosts attached to switch 1 can ping the interface Fa0/0 of the router.Given the information in the graphic and assuming that the router and switch2 are configured properly,which of the following commands should be issued on switch 1 to correct this problem?（）

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

Which name describes an IPV6 host-enable tunneling technique that uses IPV4 UDP,does not require dedicated gateway tunnels,and can pass through existing IPV4 NAT gateways?（）

Three access ports have been installed and configured to a small office.What term defines the wireless topology?（）

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?（）

A network administrator needs to configure a serial link between the main office and a remote location.The router at the remote office is a non-cisco router. How should the network administrator configure the serial interface of the main office router to make the connection?（）

A network administrator is planning a network installation for a large organization.The design requires 100 separate subnetworks,so the company has acquired a Class B network address.What subnet mask will provide the 100 subnetworks required, if 500 usable host addresses are required per subnet?（）

Which command displays the CHAP authentication process as it occurs between two routers?（）

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

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