Change the vro operating system startup sequence to solve major problems

Correct use of the vro operating system can protect the work of The vro, but changing the startup sequence of the vro operating system can also solve some problems. Here we mainly introduce the self-check process of the vro startup, this section describes how to perform self-check and find and load the operating software on the vro. In a single machine, the network administrator can set the startup sequence of the PC, such as starting from the hard disk, or from the disc and network drive. In fact, you can also change the startup sequence in the vro. Sometimes, it is very important to change the startup sequence of a vro operating system when the router operating system startup error is ruled out. Here I will introduce a command for you to quickly change the Boot sequence of the vro. With this command, the network administrator can change the startup sequence of the vro operating system as needed. Before talking about this topic, I will introduce the self-check process of the router. Knowing this process can help you understand the basic ideas and importance of changing the startup sequence of the router operating system.

Vro startup self-check process

When a vro is powered on and started, like a normal PC, the system performs a series of steps to test whether the vro-related hardware works properly and load the software required for running the vro. Vro officially referred to this series of steps as the startup sequence. Generally, there are four steps to start a vro.

Step 1: perform self-check on the vro

When a Cisco router is powered on and started, the router first executes the power-on self-check. The self-check will check the relevant hardware of the router to verify whether all the components of the device are currently operational and whether there are some hardware faults. If the self-check function is enabled, different interfaces of the vro are checked to check the working status of the vro. The boot self-check program is stored in read-only memory and runs from read-only memory.

Step 2: search for and load the operating software

If the self-check succeeds, the BootStrap program will find the available IOS (Cisco network operating system) software and load it. This program is located in read-only memory and is mainly used to execute some preparation jobs before the vro operating system runs. The BootStrap program is responsible for finding the location of each Cisco network operating system in the network, and then loading it. In general, this application looks for Cisco Network Operation pain points from flash memory, TFTP server, ROM and other locations in turn. That is to say, by default, Cisco router operating systems are all loaded from flash memory to Cisco Router network operating systems. However, if there are some problems with flash memory, the network administrator will have to change this order, so that the router operating system can be started from the TFTP server or ROM, so that our network administrator can find the problem of the router.

This is like a normal PC. By default, it is started from the hard disk. However, when there is a problem with the hard disk boot program, we sometimes need to start from the CD. Find and modify the problem, or back up some important files to prevent loss. This is similar to the operating principle of the router operating system.