What important linux commands do you find yourselves using regularly on the job

Sorry if I'm posting this in the wrong place.

Just got a software engineering job that will be heavy in networking and was told to "Refresh linux commands (networking related such as ipaddress config, netstat, interface up/down/config)"

Well, I've done little linux networking. Of course I've used ifconfig, and netstat, but I've never used interface up/down/config. Also, this sentence is super broad, and clearly infers that there are many more commands to "refresh" myself on.

​

That being said, what commands do you guys deem as the most important on the job? Things like ifconfig, telnet, netstat are obviously important, but there must be more. Also, if you have a favorite resource for linux commands I'd love to see it!

​

Thanks!