Final answer:
The last 6 hex characters for the SNMA come from the Interface Identifier, which is a unique identifier assigned to each network interface card (NIC) in a device.
Step-by-step explanation:
The last 6 hex characters for the SNMA come from the Interface Identifier. The Interface Identifier is a unique identifier assigned to each network interface card (NIC) in a device. It differentiates between devices with the same Organizationally Unique Identifier (OUI) and Network-Specific Suffix (NSS). In IPv6 addresses, the first 24 hex characters represent the OUI and NSS, while the last 40 hex characters represent the Interface Identifier.