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?（）

A network administrator is trying to add a new router into an established OSPF network.The networks attached to the new router do not appear in the routing tables of the other OSPF routers.Given the information in the partial configuration shown below,what configuration error is causing this problem?（）Router(config)#router ospf 1Router(config-router)#network 10.0.0.0 255.0.0.0 area 0

When you are troubleshooting an ACL issue on a router,which command can help you to verify which interfaces are affected by the ACL?（）

On which options are standard access list based?（）

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

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