NTP Authentication

NTP authentication can be configured, although it is optional.

It allwos NTP clients to ensure they only sync to the intended servers.

To configure NTP authentication:

1. ntp authenticate - enable NTP authentication

2. ntp autentication-key <key-number> md5 <key> - create the NTP authentication key(s).

3. ntp trusted-key <key-number> - specify the trusted key(s)

4. ntp server <ip-address> key <key-number> - specify which key to use for the server. This command isn't needed on the server (R1).