What can I Expect if I Have no Credentials
You can certainly run a discovery without any valid credentials on the devices within the network, however, the information retrieved will be a very small subset of what Open-AudIT has the ability to retrieve with credentials.
If you run discovery upon a subnet that the Server (or Collector) is not directly installed on, you can expect the following for responding devices:
IP Address
DNS Hostname and FQDN (assuming working and client populated DNS)
Open ports
An educated guess to the identity and type of device
If you run discovery upon a subnet that the Server (or Collector) is directly installed on, you can expect the following for responding devices:
IP Address
MAC Address
Manufacturer (derived from Mac Address)
DNS Hostname and FQDN (assuming working and client populated DNS)
Open ports
An educated guess to the identity and type of device
If you have working credentials, you can expect the full amount of information possible.
Obviously, the best way to use Open-AudIT is to have working credentials for the devices being discovered (be they WMI, SSH, or SNMP credentials).
We also have a page on auditing without credentials. How and Why is Open-AudIT "more secure"?#Agent?Discovery?Credentials?
In my personal opinion, the best way to find and audit every single item on your network is a Seed Discovery for each subnet, restricted to that subnet (using credentials). Seed Discoveries use switch, router and computer MAC Address tables to not miss a single device. If it is connected to the network and uses TCP/IP, a switch/router/computer has to know it is there - that's just how TCP/IP works. Combine that with custom TCP and/or UDP ports and you should then be able to determine the device type as well. But that's just my personal preference