Every node must satisfied next conditions!
4gb of ram, 1 cpu 64bit

Secure Node Criteria
Each of the following criteria must be met and maintained for a Secure Node to be eligible to recieve a share of the reward pool.These items may be added to or modified at any time.

Must maintain a balance of at least 42 ZEN in a 'stake' transparent address
Must maintain a minimum balance of .001 ZEN in a private address on the node for challenges
Must be available with minimal exception time for at least 92% of an earning period (appox. 1 day)
Must perform a challenge in under 300 seconds
Allow 8 or more peers by allowing public connections on the configured zen port (default 9033)
Must maintain a valid public SSL cert properly configured for zen
Must not fall behind the current block height by more than 4 blocks
Must update to current versions of the zen and/or tracker software within the posted time frame
Note: only one public Ip address is allowed per node (IPv4 or IPv6).

General Secure Node expectations:
Maintain the full block chain
Run on a secured system (firewall, restricted logins, etc.)
Keep the node OS updated, patched
Periodically check for notices of updates, issues, etc.
 

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If you are planning to experiment with your machine, you must have very good machine and must install Virtualbox and 1 instance of system for every node. One IP per node, I think you can't assign public IP to your virtual box..
VPS is much better solution.