At which layer of the OSI model dose PPP perform?（）

Which statement describes the rule of split horizon?（）

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?（）

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

Which command encrypts all plaintext passwords?（）

Which pairing reflects a correct protocol-and-metric relationship?（）

Which protocol reduces administrative overhead in a switched network by allowing the configuration of a new VLAN to be distributed to all the switches in a domain?（）

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

What is the subnetwork address for a host with the IP address 201.100.5.68/28?（）

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?（）