Using 31-Bit Prefixes on IPv4 Address Error: Index of the interface: Invalid IP Address

When adding a IPv4 address with 31- bit (255.255.255.254) Subnet Mask, SonicOS displays the following Status Error: Index of the interface.: Invalid IP Address.

RFC 3021 Support on SonicOS Using 31-Bit Prefixes on IPv4 Point-to-Point Links.

Support for Using 31-Bit Prefixes on IPv4 Point-to-Point Links has been added on SonicOS from 5.9.1.5 wherein 31-Bit prefixes can be configured when adding an IPv4 address on SonicWall Interface, see screenshot below taken from SonicWall 5.9.1.7 wherein a 31-Bit prefix was configured: