Support for multiple subdomains

[phihag]

By default: ip-1_2_3_4.vulnsrv.net (restricted to that IP).
Add a note to chose your own public name (that gets stored for 30 days instead of 24 hours, and is accessible from every IP). Default name: sha512(ip)[:16]. Note that everybody can access public instances.
Copy data from ip- to the public name.
Use local storage for ip-.vulnsrv.net to add a note of created public instances.
Deploy on vulnsrv.net, where *.subdomains is already aliassed.