Explanation of Router Protocol parameter settings

Many users do not pay attention to the setting of vro protocol parameters. In fact, these parameters are very important. When talking about vro protocols and vrouters, administrative distance and measurement (Metrics) are two important parameters. What do these two sets of parameters really mean? David Davis will introduce the two sets of parameters and explain the reasons why Cisco routers need to understand the importance of management parameters.

When talking about the Router Protocol and the channel used by the router, Management Distance and measurement are two important parameters. Full familiarity with these two sets of parameters plays an important role in understanding network performance, reliability, and loop selection. If you are not familiar with management spacing and metrics, you will not pay attention to them even if you see these parameters. If you enter the show ip route command, you will notice that the two parameters appear in the ARC behind the router. Here is an example: O 10.1.103.0/24 [110/791] via 10.1.100.2, 00:39:44, Serial1/0. 21. In this example, 110 indicates the management spacing, and 791 indicates the measurement. By entering the same show ip route command and specifying the router mode, you can see more detailed information. Here is an example: But what do these numbers actually mean? Let's take a closer look at the meaning of each parameter.

Management Interval

Management spacing (AD) is used to determine which channel to select when the router faces two channels of the same source. That is, if the router receives information from different sources but with the same content, which channel the router trusts. A better way is to make the best effort to select local information, and the global information is somewhat repetitive, so local information is more trustworthy. If your vro only has one vro protocol and one WAN loop, or if you only use static routing, the management distance will not affect you. However, this does not mean that you do not need to understand the role of management spacing.

But if you have a complicated network system, such as two WAN circuits, or you use two router protocols, even if one of them is a static route ), you should understand the importance of management spacing. Route resources are not only some vro protocols such as RIP, OSPF, or BGP, but also some resources connected to the vro, such as the vro interface) and Static Routing you use as the Management Server's vro), The vro selects the trusted Resource Based on the Management interval. The smaller the management interval, the more trustworthy its routing resources are.

To facilitate this decision, the router has installed a pre-program schedule table displayed in all possible resources and the default Management gap. Table A provides an example of this table. Although the distance command in vro configuration mode is used to change the manager's default Management spacing, this is usually an undesirable method .)