# Adding secondary CIDRs to pre-existing VPCs This example shows how you can use this module to apply a secondary CIDR to a pre-existing VPC. Note: If using IPAM, you can only build 1 secondary CIDR at a time. One method to do that is to use `-target`. Using the example you would uncomment the "vpc" and "ipam\_base\_for\_example\_only" modules then: 1. terraform init 1. terraform apply -target module.vpc -target module.ipam\_base\_for\_example\_only 1. terraform apply -target module.secondary ## Requirements No requirements. ## Providers | Name | Version | |------|---------| | [aws](#provider\_aws) | n/a | ## Modules | Name | Source | Version | |------|--------|---------| | [secondary](#module\_secondary) | ../.. | n/a | ## Resources | Name | Type | |------|------| | [aws_region.current](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/region) | data source | ## Inputs | Name | Description | Type | Default | Required | |------|-------------|------|---------|:--------:| | [natgw\_id\_per\_az](#input\_natgw\_id\_per\_az) | use the modules natgw\_id\_per\_az | `map(map(string))` | n/a | yes | | [vpc\_id](#input\_vpc\_id) | vpc id to create secondary cidr on | `string` | n/a | yes | ## Outputs No outputs.