1. IST 228\Ch7: Managing Cisco...1 Router Components: ROM Read-only memory (ROM) Stores: –the bootstrap program, also called the ROM Monitor, that initializes the router’s basic hardware components. –POST (power-on self test), that checks the basic functionality of the router hardware and determines interfaces. –Mini-IOS, which is used to bring up an interface. ROM monitor mode –Router mode that allows to configure your router in the event that there is no valid IOS file on your flash memory

2. IST 228\Ch7: Managing Cisco...2 Router Components: RAM RAM (1)Programs POST and bootstrap to test the equipment and locate the IOS (2) Internetwork Operating System (IOS) The IOS is located by the bootstrap program, it is loaded in to RAM (3) Command Executive Commands are loaded. (4) Running Config. File the IOS loads active configuration file (usually from NVRAM) (5) Tables ARP and routing tables (6) Buffers used for routing incoming and outgoing packets RAM stores following components:

3. IST 228\Ch7: Managing Cisco...3 Router Components: NVRAM Nonvolatile random access memory (NVRAM) –Special type of RAM –Not cleared when the router is rebooted –Startup configuration for the router is stored in NVRAM by default –Stores all the user-defined configuration information for the router

4. IST 228\Ch7: Managing Cisco...4 Router Components: Flash Memory Erasable, programmable, read-only memory (EPROM) –Not typically modified during normal operations –Can be upgraded or erased when necessary –Content of flash memory is maintained even when the router is rebooted

5. IST 228\Ch7: Managing Cisco...5 Show Commands Internetwork Operating System Programs Running Configuration Table and Buffers Backup Configuration File Operating Systems Interfaces RAMNVRAMFlash R#show process CPU R#show protocols R#show running-config R#write term R#show mem R#show stacks R#show buffers R#show startup-config R#show version R#show flash R#show interfaces

6. IST 228\Ch7: Managing Cisco...6 Startup

7. IST 228\Ch7: Managing Cisco...7 Managing Configuration Registers 16-bit software register, which is written into NVRAM. By default, it is set to load IOS from flash memory and look for startup-configuration from NVRAM...\Calc\config_register.exe

8. IST 228\Ch7: Managing Cisco...8 Checking Current Configuration

9. IST 228\Ch7: Managing Cisco...9 Chancing the Configuration Register Router(config)#config-register 0x101.  Recovering Passwords: pp. 356-359