1. Division of three types of routing
1 direct route
The direct route is discovered by the link layer protocol. It generally refers to the path to the network segment where the router's interface address is located. The direct route does not need to be manually configured. As long as the interface is configured with a network protocol address, it also manages the status, physical status and link protocol. When both are UP, the router can automatically sense the existence of the link. The IP network segment address configured on the interface will automatically appear in the routing table and be associated with the interface. It will automatically appear or disappear in the routing table as the interface status changes.
2 Static routing
Static routing is a route configured by the network administrator using commands on the router based on the network topology. This static routing information guides packet sending. The static routing method does not require the router to calculate, but it completely relies on the manual configuration of the network administrator.
In addition, the default route is a special static route. After the network management administrator manually configures the default route, when there is no matching entry between the routing table and the destination address, the router will send the data packet to the default gateway.
3 Dynamic routing
Dynamic routing means that the router can automatically establish its own routing table and dynamically adjust it according to changes in network topology status. The dynamic routing mechanism relies on the maintenance of routing tables and the dynamic exchange of routing information between routers. The exchange of routing information between routers is based on routing protocols. The ultimate purpose of exchanging routing information is to find the "best" route through the routing table.
2. The difference between the three types of routing
The main differences are based on the advantages, disadvantages and usage occasions of the three types of routing:
1 direct route
There is nothing more to say. Direct routing can only be used on directly connected router ports. There is no direct routing for non-directly connected router ports.
2 Static routing
Static routing information is private by default and will not be passed to other routers. Of course, the network administrator can also set up the router to make it shared. It is easy for network administrators to clearly understand the network topology and set correct routing information. Static routing is generally suitable for simpler network environments.
3 Dynamic routing
When the network scale is large or the network topology changes frequently, dynamic routing should be used. The router can automatically calculate new routing information according to the relevant routing algorithm to adapt to changes in the network topology. Large and complex network environments are generally not suitable for static routing. It is difficult for network administrators to fully understand the entire network topology. At the same time, when the network topology and link status change, the static routing information in the router needs to be adjusted on a large scale. This work is very difficult and complex, so dynamic routing information should be used. routing method.
3. What is the difference between static routing and static routing?
1. Static routing is generally a route manually set by the administrator, while dynamic routing is a routing entry automatically generated by the dynamic routing protocol in the router based on the network topology and specific requirements.
2. What kind of router should use what kind of routing protocol is directly determined by the network management strategy. Generally, in small and medium-sized networks, the network topology is relatively simple and there are no factors such as line redundancy, so static routing is usually used for configuration. However, large-scale networks have complex network topologies, a large number of routers, a lot of line redundancy, relatively few management personnel, and require high management efficiency. Dynamic routing protocols are usually used, appropriately supplemented by static routing.
3. Static routes are basically manually configured routes, or automatically generated by artificial related settings. If you configure an IP address, a direct route will be generated.
4. General static routing settings will not disappear after the router is restarted after being saved, but the corresponding static routes will disappear when the corresponding port is closed or invalid. On the contrary, dynamic routing will disappear, because dynamic routing can only be generated under the premise that the dynamic routing protocol operates normally.