Fortinet IPv6

Wan1: AT&T Gigabit Fiber

AT&T brought gigabit fiber from the demarc miles away to our front yard.   From this box, A fiber going into the house to the AT&T gateway.  

config ipv6
set ip6-mode dhcp
set nd-mode basic
set ip6-allowaccess ping
set icmp6-send-redirect enable
set ra-send-mtu enable
set ip6-reachable-time 0
set ip6-retrans-time 0
set ip6-hop-limit 0
set dhcp6-prefix-delegation enable
set vrrp-virtual-mac6 disable
set vrip6_link_local ::
set ip6-dns-server-override enable
config dhcp6-iapd-list
edit 1
set prefix-hint ::/60
set prefix-hint-plt 604800
set prefix-hint-vlt 2592000
next
end
end

WAN 2: Xfinity 1100+ Down/ 50 Up

config ipv6
set ip6-mode dhcp
set nd-mode basic
unset ip6-allowaccess
set icmp6-send-redirect enable
set ra-send-mtu enable
set ip6-reachable-time 0
set ip6-retrans-time 0
set ip6-hop-limit 0
set dhcp6-prefix-delegation enable
set vrrp-virtual-mac6 disable
set vrip6_link_local ::
set ip6-dns-server-override enable
config dhcp6-iapd-list
edit 2
set prefix-hint ::/60
set prefix-hint-plt 604800
set prefix-hint-vlt 2592000
next
end
end

Interface configuration

SD-WAN is configured.  

WAN 1:

set ip6-delegated-prefix-iaid 1
set ip6-upstream-interface "wan1"

WAN 2:

set ip6-delegated-prefix-iaid 2
set ip6-upstream-interface "wan2"
 

How to increment the IPV6
address:

::1 is the first address of the /60 block of 16 /64 addresses.  I use the MAC address of the interface.  ::1 to ::f is how you increment the addresses in IPv6.

set ip6-subnet ::1:xxxx:xxff:fexx:xxxx/64
config ipv6
set ip6-mode delegated
set nd-mode basic
set ip6-allowaccess ping
set icmp6-send-redirect enable
set ra-send-mtu enable
set ip6-reachable-time 0
set ip6-retrans-time 0
set ip6-hop-limit 0
set ip6-prefix-mode dhcp6
set dhcp6-prefix-delegation enable
set vrrp-virtual-mac6 disable
set vrip6_link_local ::
set ip6-dns-server-override enable
set ip6-send-adv enable
set ip6-manage-flag disable
set ip6-other-flag disable
set ip6-max-interval 600
set ip6-min-interval 198
set ip6-link-mtu 0
set ip6-default-life 1800
set ip6-delegated-prefix-iaid 1
set ip6-upstream-interface "wan1"
set ip6-subnet ::1:xxxx:xxff:fexx:xxxx/64
config dhcp6-iapd-list
edit 1
set prefix-hint ::/64
set prefix-hint-plt 604800
set prefix-hint-vlt 2592000
next
end
end

x

config ipv6
set ip6-mode delegated
set nd-mode basic
set ip6-allowaccess ping https ssh http fabric
set icmp6-send-redirect enable
set ra-send-mtu enable
set ip6-reachable-time 0
set ip6-retrans-time 0
set ip6-hop-limit 0
set ip6-prefix-mode dhcp6
set dhcp6-prefix-delegation enable
set vrrp-virtual-mac6 disable
set vrip6_link_local ::
set ip6-dns-server-override enable
set ip6-send-adv disable
set ip6-delegated-prefix-iaid 2
set ip6-upstream-interface "wan2"
set ip6-subnet ::6:xxxx:xxff:fexx:xxxx/64
config dhcp6-iapd-list
edit 2
set prefix-hint ::/60
set prefix-hint-plt 604800
set prefix-hint-vlt 2592000
next
end
end