A routing table is a data structure that is used by a router or networked computer to store the routes to various network destinations. It is used to determine the next hop for a packet based on the destination address. The routing table contains a list of routes, each consisting of a destination network and a next hop to reach that destination.
In a computer or router, the routing table is typically stored in memory and is used by the operating system or networking software to determine the best path to a given destination. When a packet is received, the destination address is looked up in the routing table and the next hop is determined based on the matching route. If there is no matching route in the table, the packet is dropped.
Routing tables can be static, meaning that the routes are manually configured by an administrator, or dynamic, meaning that the routes are learned through a routing protocol such as OSPF or BGP. Dynamic routing allows for more flexible and scalable network designs, as the routing table can be automatically updated as the network changes.
In summary, a routing table is a key component of a network, used to direct traffic to the correct destination by specifying the next hop for each packet.