Today let’s learn how BGP routing Cloudflare accepts all Cloudflare’s prefixes in fully utilized process. As a part of Server Management service, We Bobcares help you with all Cloudflare queries.

What is BGP Cloudflare?

Border Gateway Protocol (BGP) is the postal service of the Internet, for example when someone drops a letter into a mailbox, the Postal Service processes that piece of mail to choose a fast and efficient route to deliver the letter to its recipient.

Likewise, when someone submits data via the Internet, BGP is responsible for looking at all of the available paths that data could travel and picking the best route, which usually means hopping between autonomous systems.

BGP is the protocol that makes the Internet work by enabling data routing, BGP is the protocol that enables that communication to happen quickly and efficiently.

Difference between external BGP and internal BGP?

Routes are usually exchanged and traffic is transmitted over the Internet using external BGP. Autonomous systems can also use an internal version of BGP to route through their internal networks which are known as internal BGP. It should be noted that using internal BGP is not a requirement for using external BGP.

External BGP is like international shipping. When shipping a piece of mail internationally, that piece of mail reaches its destination country. However, it has to go through the destination country’s local mail service to reach its final destination.

Each country has its own internal mail service so similarly, each autonomous system can have its own internal routing protocol for routing data within its own network.

Configure the BGP session

After establishing your connection, the next steps include are: provisioning the Generic Route Encapsulation (GRE) IPs and configuring the Border Gateway Protocol (BGP) peering information. This process takes approximately one week.

​​ Provision the IP

Cloudflare can send a set of IPs that you assign to your connection before Cloudflare establishes the BGP connection. You can refer to the below example of set IPs:

Cloudflare v4: 192.0.2.10/31
Acme v4: 192.0.2.11/31
Cloudflare v6: 2001:db8:12:3::7ac2:d64a/127
Acme: 2001:db8:12:3::7ac2:d64b/127

Assign the set of IPs to your connection. Then, perform a series of ping tests to ensure that the connection have established. The ping tests confirm that packets are flowing over the link.

There might be a chance that IP provisioning may fail if you have not configured the VLAN with the VLAN.

​​Configure the BGP session

Once you provision the IPs and the ping tests confirm the connection, next accept the routes from the BGP session Cloudflare configured. Configuring the BGP session on both the Cloudflare and user sides requires a BGP call and maintenance window that you provide to Cloudflare.

After you successfully accept the BGP session, the traffic begins flowing over the CNI. Further, the traffic will start flowing. When traffic begins to flow over the connection indicates that you are fully set up with CNI.

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Conclusion

From this article, Cloudflare advertises all of its Anycast prefixes including BYOP prefixes over CNI, and the process occurs over a private link from Cloudflare to the customer data center.