Assign tunnel route priorities
Magic Transit uses a static configuration to route your traffic through Generic Routing Encapsulation (GRE) tunnels from Cloudflare’s edge to your data center(s).
You must assign a route priority to each GRE tunnel–subnet pair in your GRE configuration, as follows:
- Lower values have greater priority.
- When the priority values for prefix entries match—as illustrated by the 103.21.244.0/24 subnet in the example routing configuration (in boldface)—Cloudflare uses equal-cost multi-path (ECMP) packet forwarding to route traffic.
For more on how Cloudflare uses ECMP packet forwarding, see Traffic steering.
For an example edge routing configuration, refer to this table:
GRE tunnel | Subnet | Priority |
---|---|---|
GRE_1_IAD | 103.21.244.0/24 | 100 |
GRE_2_IAD | 103.21.244.0/24 | 100 |
GRE_3_ATL | 103.21.244.0/24 | 100 |
GRE_4_ATL | 103.21.244.0/24 | 100 |
GRE_1_IAD | 103.21.245.0/24 | 200 |
GRE_2_IAD | 103.21.245.0/24 | 200 |
GRE_3_ATL | 103.21.245.0/24 | 100 |
GRE_4_ATL | 103.21.245.0/24 | 100 |