2102 register Value

[knaik99]

why is it mandatory to have register value 2102 in running cisco router and switches ?

what will happen if we have different register value than 2102 in running cisco router and switches?

has cisco done coding like this in cisco router & Switches ?

[Reza Sharifi]

Have a look at the table in this link. It explains the config-register numbers.

https://www.cisco.com/c/en/us/support/docs/routers/10000-series-routers/50421-config-register-use.html

HTH

[Joseph W. Doherty]

"why is it mandatory to have register value 2102 in running cisco router and switches ?"

Actually it's not mandatory, just a common setting for booting up and into an IOS.

"what will happen if we have different register value than 2102 in running cisco router and switches?"

Depends what you change the value to.

"has cisco done coding like this in cisco router & Switches ?"

Sorry, I don't understand your question, unless "has" should be "why".  If the latter, you need to go back into earlier computer systems that supported a configuration register, in hardware.  Basically, you could inform the system about boot options.