Packet routing is the process of selecting paths in a network along which to send network packets. Routers use routing tables and protocols to determine the best path for data packets to travel from the source to the destination across interconnected networks. This involves analyzing various factors such as network congestion, path reliability, and the shortest distance. Effective packet routing ensures efficient data transmission and minimizes latency and packet loss.
The packet is discarded.
The router discards the packet.The router forwards the packet out the interface indicated by the default route entry.
router
Routing is the process that direct a packet to choose an optimal path from source to destination. Routing is of two types static routing and dynamic routing . Dynamic routing is not done manually and uses a number of protocols , it is automatic.
First, routing is the process a router performs when making forwarding decisions for each packet arriving at the gateway interface. To forward a packet to a destination network, the router requires a route to that network. If a route to a destination network does not exist on the router, the packet will be forwarded to the default gateway. Now, the destination network can be a number of routers or hops away from the default gateway. If the router has an entry for the network in its routing table, it would only indicate the next-hop router to which the packet is to be forwarded to and not the exact route to the final router. To sum it up, the routing process uses a routing table to map the destination address to the next hop and then forwards the packet to the next-hop address.
When a system sends an IP packet to another system in a network, it is direct routing. When a system sends an IP packet to another system via a third system or more systems in a network, it is indirect outing.
In a Cisco router, the memory that stores packet buffers and routing tables is known as Dynamic Random Access Memory (DRAM). DRAM is used for storing the operational data of the router, including routing information and temporary packet data during processing. In contrast, the router's startup configuration is stored in Non-Volatile Random Access Memory (NVRAM).
Packet forwarding in simple terms is the forwarding of packets from one node to another from networking point of view. For example, a router or a switch. These networking devices make routing devices with the help of their routing tables and then select an outgoing interface. After that they make some changes in the packet header and push (forward) the packet to the selected interface. In case you don't know the meaning of packet. Packer is the smallest unit of size in networking. Different networks has different packet size. For example, in ATM Networks the packet size is of 53 Bytes.
Multicast routing is done by sending one packet to several destinations (those destinations were announcing their interest by joining the multicast group). See [multicast].
First, routing is the process a router performs when making forwarding decisions for each packet arriving at the gateway interface. To forward a packet to a destination network, the router requires a route to that network. If a route to a destination network does not exist on the router, the packet will be forwarded to the default gateway. Now, the destination network can be a number of routers or hops away from the default gateway. If the router has an entry for the network in its routing table, it would only indicate the next-hop router to which the packet is to be forwarded to and not the exact route to the final router. To sum it up, the routing process uses a routing table to map the destination address to the next hop and then forwards the packet to the next-hop address.
Routing table
x -> routing table