There is no golden rule on this. Everyone has it’s own way to do a basic configuration on a cisco router. Here is mine.
Some routers are pre-configured by cisco. The first time that the router powers up, it will ask for a username and password which is always cisco/cisco. This is one-time-password. If you login from console and you don’t change this, then you will be locked out. In case of pre-configured router, I always erase the running configuration by issuing :
write erase reload
After the reload, the router will boot without any configuration. so this is where I start. First thing are the passwords and access to the router
en conf t hostname my_router no ip domain-lookup ip domain name my_domain service password-encryption crypto key generate rsa 2048 enable secret a-password username a-username privilege 15 secret a-password line vty 0 4 login local transport input ssh transport outpt telnet ssh line con 0 login local
I set time, timezone-summertime and logging if applicable
clock timezone ATHENS 2 0 clock summer-time ATHENS recurring last Sun Mar 3:00 last Sun Oct 4:00 service timestamps debug datetime msec localtime show-timezone service timestamps log datetime msec localtime show-timezone
Everything else does not belong to the initial config 🙂
The above configuration can be applied also on switches