Managing Access Control Lists

  • Updated on Jan 25, 2024
  • Published on Dec 15, 2021
  • 3 minute(s) read
  • Andrea Hilton
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You may use an Access Control List (ACL), which is a network access control mechanism, to prevent or allow specific MAC or IP addresses to access the unit for management purposes.

You can create up to 10 lists and each list can contain up to 40 rules. Each rule allows or blocks addresses. Rules are prioritized using the Priority field, with the rule configured with the highest priority applied first.

It is recommended to set the priorities so the most restrictive rules are performed first. For example, a high-priority rule could grant access to a specific IP address within a subnet, and the next rule could deny access to the whole subnet, thus blocking all remaining IP addresses from that subnet. Another example would be to first deny access to subnet 10.10.10.0/26, then allow access to subnet 10.10.0.0/16.

Note: Once all rules have executed, all remaining frames are dropped (this is the default rule). You must therefore ensure the addresses you want to allow are accepted by at least one rule of the ACL.

Once the ACL is created, you can then assign it to one or more interfaces. On each interface you can also select the type of protocol (CLI [SSH and Telnet], WEB, SNMP and NETCONF) to which the ACL applies.

CAUTION: If you assign a rule to an interface, you or another user may lose access to the unit.

Setting Up an ACL

To set up an ACL

  1. Access the page System â–¶ACL.
    A summary of all lists that have been configured is displayed. For more information on specific parameters, refer to the table at the end of this procedure.

  2. Click Add to add a new ACL, or click the Name of an existing ACL to edit its settings.

  3. Complete the required fields, then click Apply.

For more information on specific parameters, refer to the following tables.

ACL Definition Summary (System â–¶ACL)

Parameter Description
Name The name of the ACL list.
State The state of the list:
  • Assigned: The list is used by at least one interface.
  • Unassigned: The list is not currently used by an interface.
    		•
    Interface List Names of the interfaces using this list.

    Clicking on an interface name will open the ACL statistics, showing the number of packets hit, on a per-rule basis, for this specific interface.

    ACL Definition

    Parameter Description
    Type The type of ACL list:
    • ipsrc: IPv4 address values are filtered.
    • macsrc: MAC address values are filtered.
    Value The source addresses (IP or MAC) to filter. IP addresses can be entered using a subnet mask.

    If the Type is ipsrc:

    • Unique IPv4 address (e.g. 192.168.0.100)
    • IPv4 subnet (e.g. 192.0.2.0/24)
    If Type is macsrc:
  • Unique MAC address
    		•
    Action The filter action to take:
    • Drop: This rule drops CPU-destined frames/packets coming from the address specified in the field Value.
    • Accept: This rule accepts CPU-destined frames/packets coming from the address specified in the Value field.
    Note: Frames/packets that are dropped from a higher-priority rule cannot be recovered with an Accept rule
    Name The name of the rule.
    Priority The priority of the rule.

    Range: 1–255 (1 is the highest priority)
    State Enable or disable the rule.
    Packets The number of packets that have been intercepted by the rule:
    • If the Action is set to Accept for this rule, the number of packets accepted and sent to the CPU for processing.
    • If the Action is set to Drop for this rule, the number of packets dropped.

    Deleting an ACL

    To delete an ACL

    1. Access the page System â–¶ACL.

    2. Click the ACL Name to delete.

    3. Click Delete.

    Viewing ACL Statistics

    To view ACL statistics for each interface

    1. Access the page System â–¶ACL.

    2. Click the name of the interface in the Interface List.
      A count of Packets for each ACL rule defined is displayed. The Default Dropped Packets statistic (i.e. associated with the default rule) is displayed at the top of the page. For more information on specific parameters, refer to the table "ACL Definition Summary (System â–¶ACL)".

    3. To clear the statistics, click the Clear button.

    4. To update the statistics, click the Refresh button

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