ccna 200-301 exam fee

ccna 200-301 exam fee.|Check the configuration* backupDetermine the location of the operating systemLoad the operating system.Figure 4.2-2 Router initialization processSCCNA Study and Lab GuideAlmost all routers need to perform POST (Power-On Self Test), which is used to test the router's hardware.When the router is powered on, it performs... a series of diagnostic tests to verify its CPU, RAM and NVRAM.2. Loading the Bootstrap (Bootstrap)After the POST is completed, the bootstrap is copied from ROM to RAM and the CPU starts to execute the instructions in the bootstrap. The main function of the bootstrap is to locate the IOS and load the IOS into the RAM.The IOS operating system file, also called the IOS, contains a set of rules that govern how data is transferred through the router, manage cache space, support different network functions, update routing tables, and execute user commands. There are many versions of IOS for the same router model, and different versions of IOS support different features, such as whether they support IP advanced features, whether they support security features, whether they support voice features, and so on. The basic IOS supports fewer features, but has relatively lower hardware requirements, especially memory. Different versions of IOS have different memory requirements, and readers can choose the appropriate IOS version according to the actual application. Before loading the IOS, you first need to determine where to load the IOS from, because the image file may be in flash or ROM, or even on the network. To find where the OS image file is placed, the bootloader checks the value of the configuration register. This value can be set by a hardware jumper or by software, depending on the model of the router. The register setting specifies where the operating system is located and defines the function of other devices, such as how the router responds to keystrokes on the console keyboard and whether information from self-tests is displayed to the control terminal. The configuration register in most models of routers today is a 16-bit value stored in NVRAM, which is not a physical entity. In some older models of routers, the configuration register is a jumper with 16 pins, which is the origin of the register terminology. Whether the register is a software or hardware configuration register, the last 4 bits (or the jumper if it is a hardware register) specify the boot field, which tells the router where the configuration file is located. Software registers are represented as 4-bit hexadecimal numbers, such as 0x2142,Ox represents a hexadecimal number. Each hexadecimal digit represents a 4-bit binary number, so the first digit from the right