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

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?（）

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?（）

Which Cisco IOS diagnostics command can disrupt the operation of a router under high-load conditions?（）

If all OSPF routers in a single area are configured with the same priority value,what value dose a router use for the ODPF router ID in the absence of a loopback interface?（）

Which cisco ios command can help to determine the timing of various debug events,relative to each other,when you are debugging a complicated router issue?（）

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?（）

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