How to acquire a public IPv4 and apply it to ubuntu server? [closed]

Solution 1:

You do not. PERIOD.

IPv4 addresses are assigned in blocks, a single IP is not available OUTSIDE OF YOUR ISP (who distributes a block he has).

The whole concept of the blocks is because those blocks are the granularity of the routing tables - to keep them from growing out of control with individual IP addresses being routed.

So, talk to your ISP.