[–] Kinther [S] 0 points 1 points (+1|-0) ago 

I found this because I was researching ntp related commands used to harden a network device against attack. For my switch series, I needed to only hard code the switches permitted to interact with our devices with an access group. If you have a public facing router or switch in the list here, it may be a good idea to create a white list of devices you trust.