Logging in via SSH

ssh -l root <ip address of udm>

Checking a PPPoE Connection (NBN)

After logging in via SSH

tail -f /var/log/messages | grep pppd

The above command will let you see the PPPoE connection being established and connected if everything is OK or show you that it is failing or timing out during connection.

Changing the default site using Mongo DB Commands

https://ubntwiki.com/guides/changing_the_default_site_in_unifi