When a router boots up, it performs a series of steps, called the boot sequence, to test the hardware and load the necessary software.
1. The router performs a POST. The POST tests the hardware to verify that all components of the device are operational and present. For example, the POST checks for the different interfaces on the router. The POST is stored in and run from ROM (read-only memory).
2. The bootstrap looks for and loads the Cisco IOS software. The bootstrap is a program in ROM that is used to execute programs. The bootstrap program is responsible for finding where each IOS program is located and then loading the file. By default, the IOS software is loaded from flash memory in all Cisco routers.
3. The IOS software looks for a valid configuration file stored in NVRAM. This file is called startup-config and is only there if an administrator copies the running-config file into NVRAM.
4. If a startup-config file is in NVRAM. the router will load and run this file. The router is now operational. If a startup-config file is not in NVRAM, the router will start the setup-mode configuration upon bootup.
The router will prompt the user for a response to enter setup mode.
That's where the router's startup-config (startup configuration) is stored.That's where the router's startup-config (startup configuration) is stored.That's where the router's startup-config (startup configuration) is stored.That's where the router's startup-config (startup configuration) is stored.
**Locate and load the startup-config file from NVRAM.
The startup configuration will be erased and if the router is restarted will boot with no configuration.
The startup config is what has been saved to the memory (using write mem) and is used when the router is powered on. You can change the startup config after it has been powered up, this would be the running config. If you power the router off without saving the changes, it would revert to the startup config.
The contents of NVRAM will change
You want to totally reinitialize the router and replace the current running-config with the current startup-config. What command will you use?
It will erase start up config from NVRAM.
When a Cisco router is booted up for the first time, or is reloaded, the router will look into its Non-Volatile RAM (NVRAM) for the startup configuration file. Setup Mode is usedto configure a Cisco router or switch after start up to create a startup configuration file.
boot the router to ROM monitor mode and configure the router to ignore the startup configuration when it initializes Sorce: CCNA Final Exam Module 4 Cisco789
RouterB(config)# router rip
Router(config)#Copy running-config startup-config
It cancels only configurations settings, such as securuty, DHCP ip range, static ip settings and so on...
Here is a basic overview of the configuration of RIP on a Cisco router:Router(config)#router ripRouter(config-router)#network 192.168.1.0Router(config-router)#network 192.168.2.0Router(config-router)#network 192.168.3.0Router(config-router)#network 192.168.4.0Router(config-router)#network 192.168.5.0The 192.168.x.0 address can be changed to whatever address you would like to be broadcast over RIP. There are also other settings that can be configured.If you use RIPv2 you can also have the following configuration:Router(config)#router ripRouter(config-router)#version 2Router(config-router)#network 192.168.1.0Router(config-router)#network 192.168.2.0Router(config-router)#network 192.168.3.0Router(config-router)#network 192.168.4.0Router(config-router)#network 192.168.5.0Router(config-router)#exitRouter(config)#exitRouter#%SYS-5-CONFIG_I: Configured from console by consoleRouter#copy running-config startup-configDestination filename [startup-config]?Building configuration...[OK]Router#
It depends on model. Some models can save some data without reloading, some can't. Thus you can have partially configured router or not configured at all. But reloading is not going to damage your router.
Data Stored in the NVRAM will be erased
router>enable router#configure terminal router(config)#line vty 0 4 router(config-line)#password cisco router(config-line)#login to configure router with telnet you must set up password or secret for privilieged mode.