Effective Solution to router Loop

There are many reasons why the internet cafe router loops occur, and the solutions are also different. This article introduces the most effective solution-the D-V solution to the routing loop.

Generally, when we maintain the route table information, if the network convergence is slow after the topology changes, resulting in uncoordinated or conflicting route selection entries, the routing loop will occur.

D-V is primarily used to track changes throughout the network by periodically broadcasting route updates to all interfaces, including the complete route table. However, this will increase the burden on the cpu and bandwidth. If the convergence is too slow, a routing loop will be generated. The routing loop solution is as follows:

1. suppression timing: After a route entry is invalid, the route entry is in the suppression State for a period of time. If the router learns that a route entry is invalid from a CIDR block, the route is valid immediately on another CIDR block. The valid information is often incorrect. suppressing timing avoids this problem. When a link starts to stop frequently, suppressing timing reduces route fluctuations and increases Network stability.

2. toxicity reversal: When a route information becomes invalid, the router does not immediately delete it from the routing table, but broadcasts it with a 16, that is, an inaccessible measurement value, in this way, any loops between adjacent routers can be cleared immediately.

3. trigger update: when the route table changes, the update packet is immediately broadcast to all adjacent routers, instead of waiting for a 30-second update cycle. When a router just starts RIP, it broadcasts the request packet, the adjacent router that receives the broadcast immediately responds to an update packet, instead of waiting for the next update cycle. The changes in the network topology will spread fastest on the network, reducing the possibility of routing loops.

4. horizontal segmentation: The route information sent from one interface cannot be sent back to this interface. This method reduces the correctness and load of the route information.