An addendum to the below.  For the initial VLAN itself, we are going to use an IPv6 mask of /64 instead of /48.  The below instructions have been updated to reflect this.

IPv4: 149.112.13.0/24 

IPv6: 2001:504:105::/48

SLIX will use IPv6 2001:504:105::/64 for the first peering VLAN.

If you have an existing SLIX IP address at 204.228.158.x, add 10 to it to find your new IP address.  To find your new IPv6 address, take this number and make a decimal version of the IPv4 address.  For example:

204.228.158.4 + 10 = new IPv4 149.112.13.14/24 & IPv6 = 2001:504:105::14/64

These new subnets are live now on the SLIX infrastructure.  There is no need for administrative configuration, simply add the new IP addresses to your SLIX router interface.  I would like to remove the old SLIX subnets by June 1, 2021, so please migrate soon.