Design and modify the advanced kernel of the routing protocol for the routing protocol (1)

There are many advantages for the routing protocol of the OCTA version. Many operators use this protocol for network management. I believe that if you want to become a network administrator, you must also attach great importance to this Protocol. So, we have explained the basic overview of the routing protocol for the last few days. Now let's take a deeper look at the content. Introduction to the AODV-UCSB, which is an out-of-the-kernel daemon at the user level to implement as many logic functions as possible. This is a general design method for routing protocols because the code in the kernel has different priorities, A single error in the kernel space can cause the entire operating system to crash ｡

To implement the daemon function of the routing protocol, it must determine when to activate the routing event of the route. Since IP groups are used in fixed networks with few link interruptions and packet loss is not reported, most of the triggers are not stable and effective, the trigger time must be inferred and communicate with the routing daemon through other channels ｡

Events that must be determined

(1) When to initiate a route request

(2) How to cache data groups during route search?

(3) When Will RERR be generated if a valid route does not exist?

(4) When Will RERR be generated during the restart of the daemon ｡

Next, we will discuss different design methods. First, we should know how to determine the time and where to implement the logic of the routing protocol. We have described the advantages and disadvantages of various solutions, it also proves why we chose a daemon with a small kernel module. In addition, we discuss the importance of monitoring neighbor connection and how to implement it ｡

Design possibilities

There are many ways to implement the routing protocol to deduce the required routing event. The possible opportunities for obtaining the event are:

(1) snooping

(2) kernel modification

(3) Nerfilter

In the following, each possibility is described and their advantages and disadvantages are given ｡