A block with two or fewer addresses (/31, /32 for v4; /127, /128 for v6) reserves no network/broadcast id -- every address is a usable host (RFC 3021 for the v4 /31 case).
A block with two or fewer addresses (/31, /32 for v4; /127, /128 for v6) reserves no network/broadcast id -- every address is a usable host (RFC 3021 for the v4 /31 case).