Specify tunnel endpoints
Anycast edge IP addresses
Cloudflare assigns two Anycast IP addresses shortly after your onboarding kickoff call. Use these Anycast edge addresses as the GRE tunnel destinations on your location's routers/endpoints.
Generic Routing Encapsulation (GRE)
Cloudflare recommends two GRE tunnels for each ISP and location router combination, one per Anycast IP.
To configure the GRE tunnel(s) between Cloudflare and your locations, you must provide the following data for each tunnel:
- Customer edge IP address — A public Internet routable IP address that is outside of the prefixes Cloudflare will advertise on your behalf. These are generally IP addresses provided by your ISP. If you intend to use a physical or virtual connection (), you do not need to provide edge addresses. Cloudflare will provide them.
- Private subnet — A 31-bit subnet (/31 in CIDR notation) supporting 2 hosts, one for each side of the tunnel. Select the subnet from the following private IP space:
- Private IP addresses — The private IP address assigned to the Cloudflare and customer sides of the tunnel
Scoped routes for GRE tunnels
To reduce latency for your GRE tunnel configurations, especially if you operate your own Anycast network, Cloudflare can steer your traffic by scoping it to specific Cloudflare data center regions.
Valid Cloudflare regions include AFR, APAC, EEUR, ENAM, ME, OC, SAM, WEUR, and WNAM.
To configure scoping for your traffic, you must provide Cloudflare with GRE tunnel data for each Cloudflare region.