(第1空)Routers perform the decision process that selects what path a packet takes. These ( ) layer devices participate it the collection and distribution of network-layer information, and perform Layer 3 switching based on the contents of the network layer ( ) of each packet. You can connect the routers directly by point-to-point ( ) or local-area networks, or you can connect them by LAN or WAN switches. These Layer 2 switches unfortunately do not have the capability to hold Layer 3 ( ) information or to select the path taken by a packet through analysis of its Layer 3 destination address. Thus, Layer 2 switches be involved in the Layer 3 packet ( ) decision process.