> As long as there is a provision to soak it in CIDR. There is; the idea is to fill up random bits to /48, leaving you with 16 bits of subnetting space until y

> As long as there is a provision to soak it in CIDR. There is; the idea is to fill up random bits to /48, leaving you with 16 bits of subnetting space until you hit /64. If you're not concerned about aggregating networks, a common pattern on larger networks is to put the VLAN ID there in "false hex", i.e. VLAN 1357 = fd……:1357::/64. If you need more space you can either generate more random /48 prefixes, or widen the prefix length on your existing /48. The latter is technically against the spirit of ULAs, but… only the pedants will care.