Skip to main content

What is Configuration Register in Cisco Router/Switch

Configuration register is used to control how the router boots up, it tells the router to load the IOS from flash memory as well as to load the startup configuration from NVRAM. Config register  is a 16 bit (2 byte) value.     Default configuration register value is 0×2102 (represented in Hexadecimal Number).
Main uses of Config register Value are
  • To force the system into the ROM monitor mode
  • To select a boot source (Flash or TFTP) and default boot filename
  • To select the console terminal baud rate
  • To load operating software from ROM
  • To enable or disable the Break Function
To check the current config-register value of your Router, use this Cisco CLI command

Router#Show Version 
To change config register Value, used this Cisco CLI command
Router(config)#Config-register 0×2101
This config register value 0×2101, instructs the router to load small IOS from ROM and then show the current configuration register value.
This config-register value is also modified to recover lost passwords on a cisco Router, and for password recovery of a router the config register value is set to 0×2142.

Comments

Popular posts from this blog

What is Cisco Supervisor Engine?

Supervisor Engine is a module that is installed in the Cisco Chassis-based Catalyst Switches or Routers. Supervisor engine contains nearly all the same components of a fixed Cisco Switches or Routers. These Supervisor engines come in a variety of different types with different functionalities and are installed in the Switches/Router Chassis as per requirements of the network types.

Benefits of Supervisor Engines
By installing Latest Supervisor Engines in your existing investments (Switches and Routers) you can scale system performance and integrate next-generation services into your Networks.
Within a single multilayer switch chassis, two supervisor modules with integrated route processors can be used to provide hardware redundancy. If an entire supervisor module fails, the other module can pick up the pieces and continue operating the switch.
The supervisor engine contains the following integrated daughter cards that perform forwarding and routing and provide the protocols supported …

GNS3 Docker Error while creating node: Docker has returned an error: Cannot connect to host docker:80

Error while creating node: Docker has returned an error: Cannot connect to host docker:80 ssl:False [No such file or directory]

After adding docker template for Alpine Linux in gns3, you get above mentioned message when you want to use alpine linux in GNS3.

To get rid of this message you have to install Docker by following below link
curl -fsSL https://get.docker.com/ | sh

If you do not have curl installed then instal curl first with below command.apt-get install curl
After installing Docker you need to add your user name in the docker group with the following command. $ sudo usermod -aG docker your_username

Verify if the docker service is started with following command$ service docker status
If docker is not started then start with following command $ sudo service docker start
Logout from GNS3 Virtual Machines and log back. Start gns3 and use alpine linux.

Telnet Client is Disabled Enable it to use it from this application

This is a Cisco Network Assistant (CNA) error when you want to telnet any Cisco Devices from within CNA.
Solution to remove this error is related to Windows 7 or Windows Vista. First of all you need to Add TELNET program from Control Panel, which by Default is not added in fresh installation of Windows 7.For adding and using Telnet Program in Windows 7, Click Start > Control Panel > Uninstall a Program > Turn Windows Features On and OFF > Scroll to TELNET and Select it > Press OK After Adding Telnet Program into the Windows 7 you need to Copy Telent.exe from C:\Windows\System32 folder and paste it to C:\Windows\SysWOW64\ Now you should not get the same error.