| A | B |
|---|
| (POST) | When a Cisco router powers up, it performs a power-on self test (POST). During this self test, the router executes diagnostics from ROM on all hardware modules. These diagnostics verify the basic operation of the CPU, memory, and network interface ports. After verifying the hardware functions, the router proceeds with software initialization. |
| Steps for POST | 1) Step 1 -- The generic bootstrap loader, in ROM; 2) Step 2 -- The operating system (Cisco IOS) can be found in one of several places; 3) Step 3 -- The operating system image is loaded; 4) Step 4 -- The configuration file saved in NVRAM is loaded into main memory and executed one line at a time; 5) Step 5 -- If no valid configuration file exists in NVRAM, the operating system executes a question-driven initial configuration routine referred to as the system configuration dialog, also called the setup dialog. |
| Commands related to router startup | show startup-config and show running-config |
| setup | to bring up, quickly, a minimal configuration for any router that cannot find its configuration from some other source. |
| global parameters | the configuration values you select. |
| default answers | appear in square brackets [ ] following the question |
| No factory defaults | nothing is displayed after the question mark [ ? ]. |
| Where do you save configuration? | NVRAM |
| reload | run through the entire startup process |
| Where is the next place a router looks if it cannot find the IOS image in flash? | TFTP |
| The first global parameter | router host name |
| enable password | used when no "enable secret word" exists |
