Routed subnets

Each LAN interface (physical port + VLAN tag) on a Magic WAN Connector is part of a directly-attached subnet. When you specify a static address for the LAN interface, you indicate both the interface’s address as well as the subnet it attaches to. For example, 192.168.100.13/24 means the LAN interface has the IP address 192.168.100.13, and is part of the subnet 192.168.100.0/24.

Some LANs are more complex. In addition to the directly-attached subnet, they might have additional subnets sitting behind L3 routers south of the Magic WAN Connector. We call these routed subnets.

Refer to the diagram below for an example of how this might work:

Note

Blue represents directly-attached subnets, and red represents routed subnets.

flowchart TB
accTitle: Routed subnets
accDescr: Some LANs are complex, and might have additional subnets behind L3 routers.

a((WAN)) --> b

subgraph b [Connector]
direction TB
c(LAN 1)
d(LAN n)
end

c --- e(subnet x):::blue
d --- f(subnet 192.168.100.0/24):::blue

f---|192.168.100.10|g(Layer 3 router)

g --- h(routed subnet y):::red
g --- i(192.168.200.0/24):::red
g --- j(layer 3 router)
j --- k(routed subnet z):::red

classDef blue fill:#add8e6,color: black
classDef red fill:#ff6900,color: black

To add a routed subnet to your LAN, you need:

• A prefix: The subnet’s CIDR prefix; Cloudflare will automatically install static routes to this prefix in our global network (to forward packets for this subnet to the right Connector), and in your Connector (to forward packets for this subnet to the right LAN interface). In the figure above, the routed subnet in the center has the prefix 192.168.200.0/24.
• A next-hop address: The address of the L3 router to which the Connector should forward packets for this subnet. In the figure, the routed subnet in the center has the next-hop address 192.168.100.10.

Optionally, you can also enable NAT for a subnet by providing a static overlay prefix.

Create routed subnets

For more information on how to create routed subnets, refer to Create a LAN, either in Configure hardware Connector or Configure virtual Connector.