Lessons · Network switches · reloading
Restarting, and what that costs
`reload` restarts the switch. It comes back as its startup configuration, so anything in the running configuration that was not saved is gone.
Hone is a place to practise programming. This is one of its lessons, written out in full and free to read without an account.
What it is for
It is the single most expensive fact about a switch, and it is also, used deliberately, the only undo one has.
How to think about it
Before typing it, ask one question: is the version I want the SAVED one, or the running one? If it is the running one, save first. If somebody has just made a mess and not saved, a reload is the fastest fix there is.
Worked example
enableThe # prompt.
configure terminalInto configuration mode.
hostname GOODThe version worth keeping.
endOut.
write memorySaved, so this is what a reload would bring back.
configure terminalNow the mess.
hostname BADA change nobody wants, and nobody has saved.
endOut.
reloadThe switch restarts and reads startup-config.
enableA reboot logs you out, so you are back at Switch> and have to get to the # prompt again. That surprises people every time.
show running-configGOOD. The bad change was never written anywhere, so it simply does not exist.
Your turn
Restart the switch so it comes back as its saved configuration.
Console into a switch
The trap
Reloading to fix something after you have saved. The save made the mess permanent; the reload then loads the mess.