Configuring with additional separate IP Block of /30 via DSL

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Hi there,
Pardon me if it has been asked before but I have tried as far / hard as i could but unable to find similar problem / solution.
I have a DSL connection, connected via bridge mode (in dsl modem) by pfsense box. Plain simple PPPoE connection with as static IP, say 183.181.xx.yy with GW 183.181.xx.1.
The problem begins when I try to setup additional IP block of /30 addresses (51.99.AA.BB/30), got from my ISP.
I need some real IPs for various servers (like Web, Conferencing etc.).
I have absolutely ZERO support from my ISP. Nothing. Nichts ..

Before going to configure that /30 block, how can I be sure that this /30 block is alive, reachable ?
Then, the main question - How would I configure / setup those /30 IPs.
Please guide me considering me as pretty much new to firewalls / NAT (I thought i know at least a little bit but after dealing with this problem in pfsense type of firewall, I think i was wrong )