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Add rules

You can check for an existing root ruleset from the dashboard or via the Account rulesets API. If you are a new Magic Transit customer, you may not have a root ruleset created for your account. To view examples for root rulesets, review the Magic Firewall Terraform documentation ↗.

By default, you can create a maximum of 200 rules. We recommend you create lists of IP addresses to reference within rules to streamline rule management.

Add a rule

  1. Log in to your Cloudflare dashboard ↗, and select your account.
  2. Select Magic Firewall.
  3. In the Custom rules tab, select Add a Rule.
  4. Fill out the information for your new rule.
  5. When you are done, select Add new rule.

Create a disabled rule

When you add a new rule, the rule is Enabled by default.

To create a Disabled rule, follow the steps in Add a rule above and toggle Enabled to off. When a rule is in the disabled state, the rule will not perform the action until is set to Enabled.

To disable an existing rule, from the Magic Firewall Rules page, set the Enabled toggle to off.

Update a rule

  1. Log in to your Cloudflare dashboard ↗, and select your account.
  2. Select Magic Firewall > Custom rules.
  3. Locate the rule you want to edit, and select Edit.
  4. Update the rule with your changes and select Edit rule.

Delete an existing rule

  1. Locate the rule you want to delete in the list.
  2. From the end of the row, select Delete.
  3. Select Delete again to confirm the deletion.

API

Below, you can find examples of how to use the API to perform certain actions.

Skip action

The example below blocks all TCP ports, but allows one port (8080) by using the skip action.

Terminal window
curl https://api.cloudflare.com/client/v4/accounts/{account_id}/rulesets \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
  "name": "Example ruleset",
  "kind": "root",
  "phase": "magic_transit",
  "description": "Example ruleset description",
  "rules": [
    {
      "action": "skip",
      "action_parameters": { "ruleset": "current" },
      "expression": "tcp.dstport in { 8080 } ",
      "description": "Allow port 8080"
    },
    {
      "action": "block",
      "expression": "tcp.dstport in { 1..65535 }",
      "description": "Block all TCP ports"
    }
  ]
}'

Block a country

The example below blocks all packets with a source or destination IP address coming from Brazil by using its 2-letter country code in ISO 3166-1 Alpha 2 ↗ format.

Terminal window
curl https://api.cloudflare.com/client/v4/accounts/{account_id}/rulesets \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
  "name": "Example ruleset",
  "kind": "root",
  "phase": "magic_transit",
  "description": "Example ruleset description",
  "rules": [
    {
      "action": "block",
      "expression": "ip.geoip.country == \"BR\"",
      "description": "Block traffic from Brazil"
    }
  ]
}'

Use an IP list

Magic Firewall supports using lists in expressions for the ip.src and ip.dst fields. The supported lists are:

  • $cf.anonymizer - Anonymizer proxies
  • $cf.botnetcc - Botnet command and control channel
  • $cf.malware - Sources of malware
  • $<IP_LIST_NAME> - The name of an account-level IP list
Terminal window
curl https://api.cloudflare.com/client/v4/accounts/{account_id}/rulesets \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
  "name": "Example ruleset",
  "kind": "root",
  "phase": "magic_transit",
  "description": "Example ruleset description",
  "rules": [
    {
      "action": "block",
      "expression": "ip.src in $cf.anonymizer",
      "description": "Block traffic from anonymizer proxies"
    }
  ]
}'

Next steps

Refer to Form expressions for more information on how to write rule expressions.

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