Customize Calico Networking at Bootstrap¶

You can customize the initial Calico Installation CR by setting Ansible override variables before running bootstrap. These values are applied during bootstrap and become part of the Installation CR that the Tigera Operator reconciles.

For an overview of the operator model, see Calico Network Operator Overview (Tigera Operator).

Configurable Parameters ¶

IP pools

Variable	Default	Description
`calico_ippool_block_size_v4`	26	IPv4 block size (per-node allocation from the pool).
`calico_ippool_block_size_v6`	122	IPv6 block size.
`calico_encapsulation`	None	Encapsulation mode: `None`, `VXLAN`, `VXLANCrossSubnet`, `IPIP`, or `IPIPCrossSubnet`.

Network configuration

Variable	Default	Description
`calico_bgp`	Enabled	BGP peering: `Enabled` or `Disabled`.
`calico_host_ports`	Enabled	Host port support.
`calico_multi_interface_mode`	None	Multi-interface mode.
`calico_linux_dataplane`	Iptables	Linux dataplane mode.
`calico_windows_dataplane`	Disabled	Windows dataplane.
`calico_mtu`	(auto)	MTU value (auto-detected if not specified).

Felix configuration

Variable	Default	Description
`calico_chain_insert_mode`	Append	Iptables chain insert mode: `Append` or `Insert`.
`calico_iptables_backend`	NFT	Backend: `NFT` or `Legacy`.

Apply Custom Options at Bootstrap ¶

Provide custom variables through the Ansible override mechanism during system configuration, before running bootstrap through localhost.yml.

Example: set a custom MTU

# Bootstrap override
calico_mtu: 1450

Example: change the IPv4 block size

# Bootstrap override
calico_ippool_block_size_v4: 24

Example: set IPv4 pool values

# Bootstrap override
cluster_network_ipv4: 172.16.0.0/16
calico_ippool_block_size_v4: 26
calico_encapsulation: None

Example: set IPv6 pool values

# Bootstrap override
cluster_network_ipv6: fd00::/112
calico_ippool_block_size_v6: 122

To reconfigure Calico networking after the system is running, see Reconfigure Calico Networking After Deployment.