Small deployments in some vantage points could skip the need for an edge router if Gatekeeper servers could have a VLAN tag for IPv4 and another for IPv6. That is, instead of having only parameters front_vlan_tag and back_vlan_tag in file lua/net.lua, Gatekeeper would have front_ipv4_vlan_tag, front_ipv6_vlan_tag, back_ipv4_vlan_tag, and back_ipv6_vlan_tag.

In order for one to make this new Gatekeeper compatible with the current version, one would only need to make front_ipv4_vlan_tag equal to front_ipv6_vlan_tag, and back_ipv4_vlan_tag equal to back_ipv6_vlan_tag. So it would not break current deployments that rely on VLAN tags.