Allowing Outbound Traffic from Cloud Resources Only to a Specified Domain Name

Application Scenarios

To prevent sensitive data leakage or external attacks, you need to restrict the Internet domain names that can be accessed by cloud resources.

Use CFW to implement refined management and control on cloud resources and allow access traffic from all EIPs to a specified domain name. (Wildcard domain name *.example.com is used as an example).

Configuring CFW to Allow Cloud Resources to Access a Specified Domain Name

1. Purchase the CFW standard or professional edition. For details, see Purchasing CFW.
2. In the navigation pane on the left, click and choose Security & Compliance > Cloud Firewall. The Dashboard page will be displayed.
3. (Optional) Switch to another firewall instance. Select a firewall from the drop-down list in the upper left corner of the page.
4. Enable protection for an EIP.
   1. In the navigation pane, choose Assets > EIPs. The EIPs page is displayed. The EIP information (both IPv4 and IPv6) is automatically updated to the list.
   2. In the row of the EIP, click Enable Protection in the Operation column.

5. Configure protection rules.
   1. In the navigation pane, choose Access Control > Internet Border Protection Rules.
   2. On the Protection Rules > EIP tab page, click Add Rule. On the Add Rule page, configure protection information and set other parameters as needed.
      Configure the following protection rules:

      • One of the rule blocks all traffic, as shown in Figure 1. The priority is the lowest.

        Table 1 Blocking all traffic

        Parameter	Example Value	Description
        Direction	Inbound	Direction of the protected traffic.
        Source	Any	Origin of network traffic.
        Destination	Any	Receiver of network traffic.
        Service	Any	Protocol, source port, and destination port of network traffic.
        Application	Any	Protection policy for application layer protocols.
        Action	Allow	Action taken when traffic passes through the firewall.

        Figure 1 Blocking all traffic

        
        
      • The other rule allows the traffic to *.example.com, as shown in Figure 2. The priority is the highest.

        Table 2 Allowing the access traffic to a domain name

        Parameter	Example Value	Description
        Direction	Outbound	Direction of the protected traffic.
        Source	Any	Origin of network traffic.
        Destination	Domain Name/Domain Name Group Application type and application domain name. Enter *.example.com.	Receiver of network traffic.
        Service	TCP/1-65535/1-65535	Protocol, source port, and destination port of network traffic.
        Application	HTTP and HTTPS	Protection policy for application layer protocols.
        Action	Allow	Action taken when traffic passes through the firewall.

        • Direction: Outbound
        • Source: Any
        • Destination: Select Domain name/domain group and then Application. Select Domain name from the drop-down list and enter *.example.com.
        • Service: TCP/1-65535/1-65535
        • Application: HTTP and HTTPS
        • Action: Allow
        Figure 2 Allowing the access traffic to a domain name
        

      Specified domain names

6. View the rule hits in access control logs.

   In the navigation pane, choose Log Audit > Log Query. Click the Access Control Logs tab.

   

   In the rows where Destination IP is a domain name matching example.com, the corresponding Action is Allow. For other traffic, the Action is Block.

References

• For details about how to configure a domain name group, see Allowing Traffic from a Service to a Platform.
• For details about how to add other protection rules, see the parameter description in Adding a Protection Rule.
• For details about how to allow cloud resources to access specified domain names through the NAT gateway, see Configuring a Protection Rule to Protect SNAT Traffic.