Choose CIDR Ranges
Choosing Classless Inter-Domain Routing (CIDR) ranges is an essential part of the VPC peering process, required to ensure that data transfers successfully between Redpanda and your cloud provider.
|These are general recommendations for choosing a CIDR range to peer. If you have a complex networking setup, work with a networking engineer to identify the Redpanda CIDRs that do not conflict with your existing VPCs.|
VPC network: Before setting up a peering connection in Redpanda Cloud, you must have another VPC to which Redpanda can connect. If you do not already have a network, create one in your cloud provider.
Matching region: VPC peering connections can only be established between networks created in the same region. Redpanda Cloud does not support inter-region VPC peering connections.
Consider adding an
The following CIDR ranges are a critical part of Redpanda’s BYOC configuration:
Your existing (client) VPC CIDR
Your Redpanda cluster CIDR
It is important to ensure that these ranges do not overlap when setting up VPC peering.
To choose a range for Redpanda, you must know your VPC CIDR:
In AWS, find it in the VPC area of the AWS Management Console, labeled IPv4 CIDRs.
In GCP, find it in the Details view of your VPC, and labeled Internal IP Ranges.
The output should look similar to the following:
Address: 10.0.0.0 00001010.00000000.0000 0000.00000000 Netmask: 255.255.240.0 = 20 11111111.11111111.1111 0000.00000000 Wildcard: 0.0.15.255 00000000.00000000.0000 1111.11111111 => Network: 10.0.0.0/20 00001010.00000000.0000 0000.00000000 HostMin: 10.0.0.1 00001010.00000000.0000 0000.00000001 HostMax: 10.0.15.254 00001010.00000000.0000 1111.11111110 Broadcast: 10.0.15.255 00001010.00000000.0000 1111.11111111 Hosts/Net: 4094 Class A, Private Internet
Note the values for
HostMin (10.0.0.1) and
HostMax (10.0.15.254). These are the minimum and maximum values of the range of 4,094 IPs that this CIDR covers. The number of IPs is governed by the suffix: /16 contains 65534 IPs, /21 contains 2046, /24 contains 254, and so on. For private networks, this number can range from 8 (which contains 16777214 IPs) to 30 (which contains 2).
|The Redpanda CIDR requires a block size between /16 and /20.|
Assume that your client’s CIDR range is
10.0.0.0/20. Your Redpanda range cannot overlap with it; if it does, VPC peering will not work.
A limited set of examples that work with
10.0.1.7/20 would not work. You can use ipcalc to check for overlapping IPs.
If you have many IP ranges allocated in a complex system, seek guidance from a network engineer who can help with IP allocation. Your Redpanda CIDR cannot overlap with any of your existing VPCs, nor can it overlap with the VPC you want to peer with.
Assume that the following example ranges are in use:
A Redpanda CIDR that would work (and not overlap) with any of them is