Core - We need a "User Defined Subnet" capability
Core is using a 172.16.x.x network, and my Corporate Network already uses this same IP address space. So I have a routing conflict with my Corporate VPN, as the 172.16.x.x network exists locally on the Core, and also on my Corporate VPN.
Core needs to support RFC 1918 https://en.wikipedia.org/wiki/Private_network which will allow the Core User to define a "User Defined Subnet" for Core to use.
Most of us have to use a Corporate VPN from home, and it is imperative that the Core User has the ability to choose a "User Defined Subnet" within the RFC 1918 address spaces, so that the Core User can build a network that works properly.
Every home router I have ever purchased supports the ability to change the "User Defined Subnet" of the router.
RFC 1918 = The Private Network Address spaces that Core needs to support as a "User Defined Subnet":
10.0.0.0/8 = 10.0.0.0 – 10.255.255.255
172.16.0.0/12 = 172.16.0.0 – 172.31.255.255
192.168.0.0/16 = 192.168.0.0 – 192.168.255.255