In some Flash or EEPROM on the circuit board. You usually access these via the network using a specific IP address, like 192.68.0.1. This will vary from maker to maker, but it generally brings up a web page via a Linux based TinyWeb server inside the router. If you can't get access due to a password error, you will need to reset to factory default, but be ready to completely reconfigure it again. This is usually done by hilding the reset button depressed at power on for a period of time (5 Seconds).
The router's running configuration resides in its volatile memory (RAM). This configuration is the active set of settings that the router uses to operate and can be modified dynamically. However, it is lost when the router is powered down or restarted, unless it is saved to the non-volatile memory (NVRAM) as the startup configuration.
The commands that are displayed determine the current operation of the router.
Global configuration
Update the configuration logs
Push Button Configuration
as the commands are entered
The router command used to copy the running configuration to NVRAM is copy running-config startup-config. This command saves the current active configuration so that it will be retained after a reboot. You can also use the shorthand version wr (short for "write memory") to achieve the same result.
The running configuration on a router or switch is stored in the device's RAM (Random Access Memory) while it is running. It's a temporary configuration that is lost when the device is powered off or restarted. To view the running configuration, you can use the "show running-config" command in the device's CLI (Command Line Interface).
In order to see the running configuration on a Cisco 2600 router, follow these steps from user executive mode.RouterName> EnableRouterName# show run
copy run start
To save the running configuration on a router, you typically use the command copy running-config startup-config in the privileged EXEC mode. This command copies the current configuration stored in RAM (running-config) to NVRAM (startup-config), ensuring that the configuration is retained after a reboot. Alternatively, you can use the shorthand command write memory. Always confirm the save by checking the startup configuration with the show startup-config command.
SDRAM