Routing and switching principle routing is used to describe how to send data packets from one device to another device on different networks over the network. Vrouters do not care about these hosts. They only care about the network and the optimal route to each network. Route table creation: Direct Connection: Automatic Creation (interface dual-UP, correct IP Address Configuration) Static route. manual configuration of Dynamic Routing: dynamic learning relies on various routing protocols, such as RIP, VPN, and OSPF. Data Forwarding: the same network segment: directly encapsulate the MAC address of the other party and send the message directly. Different CIDR blocks: encapsulate the MAC address of the gateway, which is forwarded by the Gateway Router through the route table. Note: For PCs, when communicating with different network segments, you must set a default gateway. Routing principle: the best routing priority and longest matching principle.