Help Center/ Cloud Firewall/ Best Practices/ Allowing Internet Traffic Only to a Specified Port
Updated on 2025-09-29 GMT+08:00

Allowing Internet Traffic Only to a Specified Port

Application Scenarios

For security purposes, you need to allow traffic only from certain ports (such as ports 80 and 443) to access cloud resources.

This section describes how to configure CFW for refined management and control on cloud resources, allowing all EIPs to access port 80 of an EIP (xx.xx.xx.1).

Configuring CFW to Allow the Access Traffic from the Internet to a Specified Port

  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 the EIP (xx.xx.xx.1).

    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 (xx.xx.xx.1), 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 rule blocks all traffic and has the lowest priority.
        • Direction: Inbound
        • Source: Any
        • Destination: Any
        • Service: Any
        • Application: Any
        • Action: Block
        Figure 1 Blocking all traffic


      • The other rule allows the traffic from port 80 of EIP (xx.xx.xx.1) and has the highest priority.
        Figure 2 Allowing access traffic to port 80 of xx.xx.xx.1
        Table 1 Allowing access traffic to port 80 of xx.xx.xx.1

        Parameter

        Example Value

        Description

        Direction

        Inbound

        Direction of the protected traffic.

        Source

        Any

        Origin of network traffic.

        Destination

        Select IP address and enter xx.xx.xx.1.

        Receiver of network traffic.

        Service

        TCP/1-65535/80

        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.

  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 xx.xx.xx.1, the corresponding Action is Block.

References

For details about how to add other protection rules, see the parameter description in Adding a Protection Rule.