There are many reasons for the Internet café router to occur, of course, the solution is different. This article describes the most effective way to solve the routing loop--d-v.
Usually, when we maintain the routing table information, if the topology changes, the network convergence slowly produces the uncoordinated or contradictory routing entries, and the routing loop problem occurs.
The primary role of D-V is to track changes to the entire network by periodically broadcasting routing updates to all interfaces, which include a complete routing table. However, this will add to the CPU and bandwidth burden, if the convergence update too slow will produce routing loops, routing loop solution is as follows:
1. Suppress timings: After a routing message is invalid, this route is suppressed for a period of time, if the router from a network segment to know that a path failure, immediately on another network segment to know that the route is effective, this effective information is often incorrect, suppress the timing to avoid this problem, When a link stops frequently, the suppression timing reduces the drift of the route and increases the stability of the network.
2. Toxicity reversal: When a path information becomes invalid, the router does not immediately remove it from the routing table, but instead broadcasts it by 16, an unreachable measure, so that any loops between adjacent routers can be cleared immediately.
3. Trigger UPDATE: When the routing table changes, the update message immediately broadcast to all neighboring routers, rather than waiting for a 30-second update cycle, when a router just started RIP, it broadcast request message, received this broadcast adjacent routers immediately answer an update message, without waiting for the next update cycle, The change of network topology will spread on the network as fast as possible, and reduce the possibility of routing loop generation.
4. Horizontal segmentation: Specify that routing information sent out by an interface can no longer be sent back to this interface. This approach reduces the correctness and load of routing information.