多项选择题 Which three Layer 2 encapsulation types would be used on a WAN rather than a LAN?（）

多项选择题 A Catalyst 2950 needs to be reconfigured. What steps will ensure that the old configuration is erased?（）

多项选择题 A network administrator issues the ping 192.168.2.5 command and successfully tests connectivity to a host that has been newly connected to the network. Which protocols were used during the test?（）