One IPv6 prefix per lan

My ISP is AT&T and the AT&T gateway will only delegate downstream routers a /64 despite having a /60 for itself. There's no way to ask it for something larger than a /64 which unfortunately limits me to one lan network however I've read on the AT&T forums that it's possible to have your DHCP client ask for multiple /64s. I have two questions, first how would I go about getting OpenWRT to ask for multiple /64s from my gateway? My second question is in regards to the way OpenWRT assigns prefixes. OpenWRT likes to give a /64 to all LAN interfaces from each prefix it receives however seeing these will be /64s already I'll still be stuck with only 1 lan. Is there a way to manually assign one and only one /64 to a given lan? My end goal is to get the AT&T gateway to give OpenWRT 3 /64s out of my 16 available and then assign them so I can have a LAN, a DMZ, and a guest wifi. Hopefully this isn't too convoluted.

It should be something like this:

uci set network.wan62="interface"
uci set network.wan62.ifname="@wan"
uci set network.wan62.proto="dhcpv6"
uci set network.lan.ip6class="wan6"
uci set network.lan2.ip6class="wan62"
uci commit network
service network restart

Hmmmm, both interfaces get the same prefix which I assume is because they're coming from the same MAC. Either that or it's something with the DHCP client ID but I haven't figured out how to change that without breaking the interface.

uci set network.wan62.clientid="INCREMENTED_WAN_MAC_ADDRESS"
ifup wan62; sleep 10; ifstatus wan62

Doing that causes wan62 to never come up. I did a ps | grep dhcp and there's this new process
/bin/sh ./dhcpv6.sh dhcpv6 setup wan62 {"ifname":"@wan6","proto":"dhcpv6","clientid":"INCREMENTED_WAN_MAC_ADDRESS"} eth3
but only a single odhcp6c -s /lib/netifd/dhcpv6.script -Ntry -P0 -t120 eth3 I was expecting there to be two instances of odhcp, one for each interface. That one instance is from the wan6 interface. Maybe I should try updating OpenWRT. I'm currently on 18.06.1

Try to remove the delimiters ":" leaving only hex numbers.

I'm not sure I understand what this is in reference to

Find the MAC address of your WAN interface.
Change the last digit and try to use it as client ID.
If this doesn't work, try other notations.

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That worked, thanks so much for your help

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That's not an easy one as there's multiple pieces to the answer in order for it to work as intended. I don't think I can mark multiples right?

No, just a single posting can be marked.

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