Latest revision as of 09:16, 1 December 2014

Cisco 1841

Console to the router with Tetra Term and send Break (alt+b) at POST. Literally power off/on and send break straight after 2 seconds or when you see the first lines of booting messages.
```
rommon 1 > confreg 0x2142 
You must reset or power cycle for new config to take effect 
rommon 2 > reset
```
Answer No or press ctrl+c to skip auto configuration
Type enable>
Type configure memory or copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.
Type configure terminal
Type enable secret <password> in order to change the enable secret password
Issue the no shutdown command on every interface that you use.
Type config-register <configuration_register_setting>. Where configuration_register_setting is either the value you recorded or 0x2102
```
hostname(config)#config-register 0x2102
```
Type end and write memory or copy running-config startup-config to save changes
Type reload

The configuration register tells the router how to boot. There are many possible settings for the configuration register. The most common ones are:

0x2102 - Factory default setting for Cisco routers (load the IOS image from flash and load the startup config file from NVRAM)
0x2142 - Router ignores the contents of Non-Volatile RAM (NVRAM)
0x2120 - Router boots into ROMmon mode

@@ Line 12: / Line 12: @@
 # Type <tt>end</tt> and <tt>write memory</tt> or <tt>copy running-config startup-config</tt> to save changes
 # Type  <tt>reload</tt>
+= Configuration register =
+The configuration register tells the router how to boot. There are many possible settings for the configuration register. The most common ones are:
+*0x2102 - Factory default setting for Cisco routers (load the IOS image from flash and load the startup config file from NVRAM)
+*0x2142 - Router ignores the contents of Non-Volatile RAM (NVRAM)
+*0x2120 - Router boots into ROMmon mode