ccna certification no degree

ccna certification no degree.FLASH 1-> ICQ ground os|TFTP version of the word . Execute IOSNVRAM - File1 Fl r Technical Desk - ExecutionFigure 4-1 Router startup process1. Performing Power-On Self Test and Loading Bootstrap ProgramThe POST (Power-On Self Test, POST) process is used to detect the router hardware. When the router is powered up, the software on the ROM chip performs POST for diagnostics, mainly for hardware components such as CPU, RAM, and NVRAM. After POST is complete, the router executes the bootstrap process. The bootstrap program copies the IOS image file from ROM to RAM, and then the CPU executes the instructions in the bootstrap program. The main task of the bootstrap program is to find the IOS image file and load it into RAM.Chapter 4 Routing Concepts . 53 .2. finding and loading the IOSThe IOS image file is usually stored in flash memory or may be stored on another location such as a TFTP server. After you find the IOS image file and start loading the IOS. you will see a string of #'s during the image file decompression process. The order in which the router looks for the IOS image also depends on the Configuration Register's boot field and other settings (e.g., the boot system command can specify the order in which to look for the IOS). The configuration register is a 2-byte register, the lower 4 bits are the boot field, different values represent different locations to find the IOS, by default the register value is 0x2102, i.e. the value of the boot field is 2. By default the router looks for the IOS from Flash first, then the TFTP server. If the IOS image file cannot be found, the router will enter the monitoring (Rommon) mode.