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Access Control List (ACL)

Access Control Lists (ACLs) in the Cloud Management Portal are an essential network security feature that governs how traffic flows between network tiers within a VPC and external networks. This guide provides an in-depth overview of ACLs, their purpose, and a step-by-step process to create and manage ACL rules.

Overview of Network ACLs​

An Access Control List (ACL) in the Cloud Management Portal is a collection of network traffic filtering rules applied to a specific network tier within a Virtual Private Cloud (VPC). These rules define whether to allow or deny ingress (incoming) and egress (outgoing) traffic based on parameters like source/destination CIDR, protocol, and port range.

Each ACL:

  • Is associated with a VPC.

  • Can be assigned to one or more network tiers within that VPC.

  • Controls traffic between tiers, the public internet, or other external networks.

  • Must be explicitly assigned to a network tier (only one ACL per tier is allowed).

Default ACLs​

When no custom ACL is defined, the portal provides two default ACLs:

S. NoNameDescription
1default_allowPermits all incoming and outgoing traffic
2default_denyBlocks all incoming and outgoing traffic

Note: Default ACLs cannot be modified or deleted.

How ACL Rules Are Processed​

  • Rule Order Matters: ACL rules are evaluated in order, starting with the lowest rule number. The first match determines the action (allow or deny).

  • Unidirectional: Ingress and egress rules are independent. An ingress rule to allow traffic does not automatically permit the response to that traffic via egress.

For example:

  • An ingress rule that allows TCP traffic on port 80 does not imply egress traffic on the same port is allowed.

  • You must define both ingress and egress rules if bidirectional communication is required.

Behavior of Newly Created ACLs​

  • By default, a newly created ACL:

    • Denies all incoming traffic

    • Allows all outgoing traffic

To adjust this behavior:

  • Add an "allow all ingress" rule (e.g., CIDR 0.0.0.0/0)

  • Add a "deny all egress" rule if stricter controls are needed.

Creating an ACL and ACL Rule​

1. Accessing the VPC Section :​

  • Log in to your Cloud Management Portal using your authorized credentials.

  • From the left navigation pane, go to:

    Network → VPC

  • You will see a list of all existing VPC networks associated with your cloud account.

2. Access ACL Management :​

  • Click the VPC name to view its details.
  • On the VPC details page, click the Configure button.
  • Under the Router Section, click Network ACL List

3. Create a New ACL List :​

  • Click the Add ACL List button.

  • In the popup:

    • Name: Enter a descriptive name (e.g., Web-Tier-Allow-All)

    • Description: Optionally describe the purpose of this ACL.

  • Click Add

  • Your new ACL list will now appear in the ACL list view.

4. Add Rules to the ACL List :​

  • Click the name of your newly created ACL to manage its rules.

  • Navigate to the ACL List Rules tab.

  • Click the Add Rule button.

5. Configure ACL Rule Details :​

  • In the popup window, fill in the required fields:

    • Rule Number : Determines the order of rule evaluation. Lower numbers are evaluated first.

    • CIDR : CIDR block for source (ingress) or destination (egress).

      • Use 0.0.0.0/0 to apply to all IPs
      • E.g., 192.168.0.0/24

    • Action : Choose Allow or Deny to permit or block matching traffic.

    • Protocol : Select protocol: TCP, UDP, ICMP, or All.

      • You can also specify a custom protocol number.

    • Start Port / End Port : For TCP/UDP: define port range. Use same port number in both fields for a single port (e.g., 22 for SSH).

    • ICMP Type / Code : For ICMP rules only: define the ICMP type and code (e.g., Type 8 for Echo Request).

    • Traffic Type : Select Ingress (incoming) or Egress (outgoing).

  • Example Rule : Allow all HTTP inbound traffic to a web tier:

    • Rule Number: 100

    • CIDR: 0.0.0.0/0

    • Action: Allow

    • Protocol: TCP

    • Start Port: 80, End Port: 80

    • Traffic Type: Ingress

6. Save the Rule :​

  • Once all fields are filled, click Add

  • The rule will now appear in the ACL Rules list under the ACL List Rules tab.