NVRAM, TFTP,Console
The "default gateway" is your router.
The reset button in a router let you remove all the configuration you do and gives you the default configuration from factory.
0x2102
Which default EIGRP configuration must be modified to allow an EIGRP router to advertise subnets that are configured with VLSM
When a router boots up, it follows a default order to search for startup configuration information. First, it checks the non-volatile memory (NVRAM) for the startup configuration file, typically named "startup-config." If it doesn't find a valid configuration there, it may look for a configuration file in a TFTP server, and if that fails, the router will proceed with its default settings, often leading to a mode where no configurations are applied.
When resetting a Cisco 1841 router, the default password recovery and administration key is "confreg 0x2142." This allows you to reset the router with a new configuration.
Reload the device.
autosummarization
The router will prompt the user for a response to enter setup mode.
It is always good practice to change the default password to something else. If it is a wireless router you should also change the default SSID and enable an encryption method.
When you see a string of hash marks (###) during a console connection after powering on a router, it typically indicates that the device is in a boot sequence and is running through its initialization process. This usually happens when the router is loading its operating system and configuration files. The hash marks signify that the device is in a state of waiting or processing, often related to the loading of the IOS (Internetwork Operating System) or other necessary components. If the sequence continues without progressing, it may indicate an issue with the device's boot process.
Flash memory