Out-of-band management: a way in that does not depend on the network

The idea

An admin laptop manages coreRouter, the Router between the office and an app server, over SSH. Manage a network over a separate one, so a mistake on the first does not lock you out: out of band management.

Steps

1. In-band management

   Most networks are managed over themselves, and that has a weak spot. The admin manages coreRouter from the office, over the office's own cable. core is the admin's name for the router.

   adminLaptop:~# ssh core hostname
   adminLaptop:~# curl -s -m3 10.0.2.10

2. One wrong command

   Changes are made over the network itself, so one mistake can cut the admin off. Over that session, the admin means to shut an unused card and shuts the office card, officeNetwork, instead.

   adminLaptop:~# ssh core ip link set officeNetwork down
   adminLaptop:~# ssh core hostname
   adminLaptop:~# curl -s -m3 10.0.2.10