Recommended DNS policies

We recommend you add the following DNS policies to build an Internet and SaaS app security strategy for your organization.

All-DNS-Domain-Allowlist

Allowlist any known domains and hostnames. With this policy, you ensure that your users can access your organization's domains even if the domains fall under a blocked category, such as Newly Seen Domains or Login Screens.

Dashboard

Selector	Operator	Value	Logic	Action
Domain	in list	Known Domains	Or	Allow
Host	in list	Known Domains

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rules \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
--data '{
  "name": "All-DNS-Domain-Allowlist",
  "description": "Allowlist any known domains and hostnames",
  "precedence": 0,
  "enabled": true,
  "action": "allow",
  "filters": [
    "dns"
  ],
  "traffic": "any(dns.domains[*] in $<KNOWN_DOMAINS_LIST_UUID>) or dns.fqdn in $<KNOWN_DOMAINS_LIST_UUID>"
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "dns_whitelist_policy" {
  account_id  = var.account_id
  name        = "All-DNS-Domain-Allowlist"
  description = "Allowlist any known domains and hostnames"
  precedence  = 0
  enabled     = true
  action      = "allow"
  filters     = ["dns"]
  traffic     = "any(dns.domains[*] in ${"$"}${cloudflare_zero_trust_list.domain_whitelist.id}) or dns.fqdn in ${"$"}${cloudflare_zero_trust_list.domain_whitelist.id}"
}

Quarantined-Users-DNS-Restricted-Access

Restrict access for users included in an identity provider (IdP) user group for risky users. This policy ensures your security team can restrict traffic for users of whom malicious or suspicious activity was detected.

Dashboard

Selector	Operator	Value	Logic	Action
Domain	not in list	Allowed Remediation Domains	Or	Block
Host	not in list	Allowed Remediation Domains	And
User Group Names	in	Quarantined Users

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rules \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
--data '{
  "name": "Quarantined-Users-DNS-Restricted-Access",
  "description": "Restrict access for users included in an identity provider (IdP) user group for risky users",
  "precedence": 10,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "not(any(dns.domains[*] in $<ALLOWED_REMEDIATION_DOMAINS_LIST_UUID>)) or not(any(dns.domains[*] in $<ALLOWED_REMEDIATION_DOMAINS_LIST_UUID>))",
  "identity": "any(identity.groups.name[*] in {\"Quarantined Users\"})"
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "dns_restrict_quarantined_users" {
  account_id  = var.account_id
  name        = "Quarantined-Users-DNS-Restricted-Access"
  description = "Restrict access for users included in an identity provider (IdP) user group for risky users"
  precedence  = 10
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "not(any(dns.domains[*] in ${"$"}${cloudflare_zero_trust_list.allowed_remediation_domains.id})) or not(any(dns.domains[*] in ${"$"}${cloudflare_zero_trust_list.allowed_remediation_domains.id}))"
  identity    =  "any(identity.groups.name[*] in {\"Quarantined Users\"})"
}

All-DNS-SecurityCategories-Blocklist

Block security categories, such as Command and Control & Botnet and Malware, based on Cloudflare's threat intelligence.

Dashboard

Selector	Operator	Value	Action
Security Categories	in	All security risks	Block

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rule \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
--data '{
  "name": "All-DNS-SecurityCategories-Blocklist",
  "description": "Block security categories based on Cloudflare's threat intelligence",
  "precedence": 20,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "any(dns.security_category[*] in {68 178 80 83 176 175 117 131 134 151 153})",
  "identity": ""
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "block_security_threats" {
  account_id  = var.account_id
  name        = "All-DNS-SecurityCategories-Blocklist"
  description = "Block security categories based on Cloudflare's threat intelligence"
  precedence  = 20
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "any(dns.security_category[*] in {68 178 80 83 176 175 117 131 134 151 153})"
}

All-DNS-ContentCategories-Blocklist

Entries in the security risk content subcategory, such as New Domains, do not always pose a security threat. We recommend you first create an Allow policy to track policy matching and identify any false positives. You can add false positives to your Trusted Domains list used in All-DNS-Domain-Allowlist.

After your test is complete, we recommend you change the action to Block to minimize risk to your organization.

Dashboard

Selector	Operator	Value	Action
Content Categories	in	Questionable Content, Security Risks, Miscellaneous	Block

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rule \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
--data '{
  "name": "All-DNS-ContentCategories-Blocklist",
  "description": "Block common content categories that may pose a risk",
  "precedence": 30,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "any(dns.content_category[*] in {17 85 87 102 157 135 138 180 162 32 169 177 128 15 115 119 124 141 161})",
  "identity": ""
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "block_content_categories" {
  account_id  = var.account_id
  name        = "All-DNS-ContentCategories-Blocklist"
  description = "Block common content categories that may pose a risk"
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "any(dns.content_category[*] in {17 85 87 102 157 135 138 180 162 32 169 177 128 15 115 119 124 141 161})"
  identity    = ""
}

All-DNS-Application-Blocklist

Block unauthorized applications to limit your users' access to certain web-based tools and minimize the risk of shadow IT. For example, the following policy blocks known AI tools:

Dashboard

Selector	Operator	Value	Action
Application	in	Artificial Intelligence	Block

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rule \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN>" \
--data '{
  "name": "All-DNS-Application-Blocklist",
  "description": "Block access to unauthorized AI applications",
  "precedence": 40,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "any(app.type.ids[*] in {25})",
  "identity": ""
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "block_unauthorized_apps" {
  account_id  = var.account_id
  name        = "All-DNS-Application-Blocklist"
  description = "Block access to unauthorized AI applications"
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "any(app.type.ids[*] in {25})"
  identity    = ""
}

All-DNS-GeoCountryIP-Blocklist

Block websites hosted in countries categorized as high risk. The designation of such countries may result from your organization's users or through the implementation of regulations including EAR ↗, OFAC ↗, and ITAR ↗.

Dashboard

Selector	Operator	Value	Action
Resolved Country IP Geolocation	in	Afghanistan, Belarus, Congo (Kinshasa), Cuba, Iran, Iraq, Korea (North), Myanmar, Russian Federation, Sudan, Syria, Ukraine, Zimbabwe	Block

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rules \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
--data '{
  "name": "All-DNS-GeoCountryIP-Blocklist",
  "description": "Block traffic hosted in countries categorized as high security risks",
  "precedence": 50,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "any(dns.dst.geo.country[*] in {\"AF\" \"BY\" \"CD\" \"CU\" \"IR\" \"IQ\" \"KP\" \"MM\" \"RU\" \"SD\" \"SY\" \"UA\" \"ZW\"})"
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "dns_geolocation_block_policy" {
  account_id  = var.account_id
  name        = "All-DNS-GeoCountryIP-Blocklist"
  description = "Block traffic hosted in countries categorized as high security risks"
  precedence  = 50
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "any(dns.dst.geo.country[*] in {\"AF\" \"BY\" \"CD\" \"CU\" \"IR\" \"IQ\" \"KP\" \"MM\" \"RU\" \"SD\" \"SY\" \"UA\" \"ZW\"})"
}

All-DNS-DomainTopLevel-Blocklist

Block frequently misused top-level domains (TLDs) to reduce security risks, especially when there is no discernible advantage to be gained from allowing access. Similarly, restricting access to specific country-level TLDs may be necessary to comply with regulations such as OFAC ↗ and ITAR ↗.

Dashboard

Selector	Operator	Value	Action
Domain	matches regex	[.](cn|ru)$ or [.](rest|hair|top|live|cfd|boats|beauty|mom|skin|okinawa)$ or [.](zip|mobi)$	Block

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rules \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
--data '{
  "name": "All-DNS-DomainTopLevel-Blocklist",
  "description": "Block DNS queries of known risky TLDs",
  "precedence": 60,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "any(dns.domains[*] matches \"[.](cn|ru)$ or [.](rest|hair|top|live|cfd|boats|beauty|mom|skin|okinawa)$ or [.](zip|mobi)$\")"
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "dns_blacklist_policy" {
  account_id  = var.account_id
  name        = "All-DNS-DomainTopLevel-Blocklist"
  description = "Block DNS queries of known risky TLDs"
  precedence  = 60
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "any(dns.domains[*] matches \"[.](cn|ru)$ or [.](rest|hair|top|live|cfd|boats|beauty|mom|skin|okinawa)$ or [.](zip|mobi)$\")"
}

All-DNS-DomainPhishing-Blocklist

Block misused domains to protect your users against sophisticated phishing attacks, such as domains that specifically target your organization. For example, the following policy blocks specific keywords associated with an organization or its authentication services (such as okta, 2fa, cloudflare and sso) while still allowing access to known domains.

Dashboard

Selector	Operator	Value	Logic	Action
Domain	not in list	Known Domains	And	Block
Domain	matches regex	.*okta.*|.*cloudflare.*|.*mfa.*|.sso.*

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rules \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
--data '{
  "name": "All-DNS-DomainPhishing-Blocklist",
  "description": "Block misused domains used in phishing campaigns",
  "precedence": 70,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "any(dns.domains[*] matches \".*okta.*|.*cloudflare.*|.*mfa.*|.sso.*\") and not(any(dns.domains[*] in $<KNOWN_DOMAINS_LIST_UUID>))"
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "dns_phishing_domains_block" {
  account_id  = var.account_id
  name        = "All-DNS-DomainPhishing-Blocklist"
  description = "Block misused domains used in phishing campaigns"
  precedence  = 70
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "any(dns.domains[*] matches \".*okta.*|.*cloudflare.*|.*mfa.*|.sso.*\") and not(any(dns.domains[*] in ${"$"}${cloudflare_zero_trust_list.known_phishing_domains_list.id}))"
}

All-DNS-ResolvedIP-Blocklist

Block specific IP addresses that are malicious or pose a threat to your organization.

You can implement this policy by either creating custom blocklists or by using blocklists provided by threat intelligence partners or regional Computer Emergency and Response Teams (CERTs). Ideally, your CERTs can update the blocklist with an API automation to provide real-time threat protection.

Dashboard

Selector	Operator	Value	Action
Resolved IP	in list	IP Blocklist	Block

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rules \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
--data '{
  "name": "All-DNS-ResolvedIP-Blocklist",
  "description": "Block specific IP addresses deemed to be a risk to the Organization",
  "precedence": 80,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "any(dns.resolved_ips[*] in $<IP_BLOCKLIST_UUID>)"
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "dns_resolvedip_blocklist_rule" {
  account_id  = var.account_id
  name        = "All-DNS-ResolvedIP-Blocklist"
  description = "Block specific IP addresses deemed to be a risk to the Organization"
  precedence  = 80
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "any(dns.resolved_ips[*] in ${"$"}${cloudflare_zero_trust_list.ip_blocklist.id}"
}

All-DNS-DomainHost-Blocklist

Block specific domains or hosts that are malicious or pose a threat to your organization. Like All-DNS-ResolvedIP-Blocklist, this blocklist can be updated manually or via API automation.

Dashboard

Selector	Operator	Value	Logic	Action
Domain	in list	Domain Blocklist	Or	Block
Host	in list	Host Blocklist	Or
Host	matches regex	.*example\.com

API

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/gateway/rules \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $CLOUDFLARE_API_TOKEN>" \
--data '{
  "name": "All-DNS-DomainHost-Blocklist",
  "description": "Block specific domains or hosts that are malicious or pose a threat to your organization.",
  "precedence": 90,
  "enabled": true,
  "action": "block",
  "filters": [
    "dns"
  ],
  "traffic": "any(dns.domains[*] in $<DOMAIN_BLOCKLIST_UUID>) and dns.fqdn in $<HOST_BLOCKLIST_UUID> and dns.fqdn matches \".*example\\.com\""
}'

Terraform

resource "cloudflare_zero_trust_gateway_policy" "block_dns_domain_host" {
  account_id  = var.account_id
  name        = "All-DNS-DomainHost-Blocklist"
  description = "Block specific domains or hosts that are malicious or pose a threat to your organization."
  precedence  = 90
  enabled     = true
  action      = "block"
  filters     = ["dns"]
  traffic     = "any(dns.domains[*] in ${"$"}${cloudflare_zero_trust_list.domain_blocklist.id}) and dns.fqdn in ${"$"}${cloudflare_zero_trust_list.host_blocklist.id} and dns.fqdn matches \".*example\\.com\""
}