Extended ACLs and Extended ACL6s

Extended ACLs and extended ACL6s provide parameters and actions not available with simple ACLs. You can filter data based on parameters such as source IP address, source port, action, and protocol. You can specify tasks to allow a packet, deny a packet, or bridge a packet.

Extended ACLs and ACL6s can be modified after they are created, and you can renumber their priorities to specify the order in which they are evaluated.

Note: If you configure both simple and extended ACLs, simple ACLs take precedence over extended ACLs.

The following actions can be performed on extended ACLs and ACL6s: Modify, Apply, Disable, Enable, Remove, and Renumber (the priority). You can display extended ACLs and ACL6s to verify their configuration, and you can display their statistics.

You can configure the Citrix ADC to log details for packets that match an extended ACL.

Applying Extended ACLs and Extended ACL6s: Unlike simple ACLs and ACL6s, extended ACLs and ACL6s created on the Citrix ADC do not work until they are applied. Also, if you make any changes to an extended ACL or ACL6, such as disabling the ACLs, changing a priority, or deleting the ACLs, you must reapply the extended ACLs or ACL6s. You must reapply them after enabling logging. The procedure to apply extended ACLs or ACL6s reapplies all of them. For example, if you have applied extended ACL rules 1 through 10, and you then create and apply rule 11, the first 10 rules are applied afresh.

If a session has a DENY ACL related to it, that session is terminated when you apply the ACLs.

Extended ACLs and ACL6s are enabled by default. When they are applied, the Citrix ADC starts comparing incoming packets against them. However, if you disable them, they are not used until you reenable them, even if they are reapplied.

Renumbering the priorities of Extended ACLs and Extended ACL6s: Priority numbers determine the order in which extended ACLs or ACL6s are matched against a packet. An ACL with a lower priority number has a higher priority. It is evaluated before ACLs with higher priority numbers (lower priorities), and the first ACL to match the packet determines the action applied to the packet.

When you create an extended ACL or ACL6, the Citrix ADC automatically assigns it a priority number that is a multiple of 10, unless you specify otherwise. For example, if two extended ACLs have priorities of 20 and 30, respectively, and you want a third ACL to have a value between those numbers, you might assign it a value of 25. If you later want to retain the order in which the ACLs are evaluated but restore their numbering to multiples of 10, you can use the renumber procedure.

Configuring Extended ACLs and Extended ACL6s

Configuring an extended ACL or ACL6 on a Citrix ADC consists of the following tasks.

• Create an extended ACL or ACL6. Create an extended ACL or ACL6 to either allow, deny, or bridge a packet. You can specify an IP address or range of IP addresses to match against the source or destination IP addresses of the packets. You can specify a protocol to match against the protocol of incoming packets.
• (Optional) Modify an extended ACL or ACL6. You can modify extended ACLs or ACL6s that you previously created. Or, if you want to temporarily take one out of use you can disable it, and later reenable it.
• Apply extended ACLs or ACL6s. After you create, modify, disable or reenable, or delete an extended ACL or ACL6, you must apply the extended ACLs or ACL6s to activate them.
• (Optional) Renumber the priorities of extended ACLs or ACL6s. If you have configured ACLs with priorities that are not multiples of 10 and want to restore the numbering to multiples of 10, use the renumber procedure.

CLI procedures

To create an extended ACL by using the CLI:

At the command prompt, type:

• **add ns acl** <aclname> <aclaction> [-**srcIP** [<operator>] <srcIPVal>] [-**srcPort** [<operator>] <srcPortVal>] [-**destIP** [<operator>] <destIPVal>] [-**destPort** [<operator>] <destPortVal>] [-**TTL** <positive_integer>] [-**srcMac** <mac_addr>] [(-**protocol** <protocol> [-established]) | -**protocolNumber** <positive_integer>] [-**vlan** <positive_integer>] [-**interface** <interface_name>] [-**icmpType** <positive_integer> [-**icmpCode** <positive_integer>]] [-**priority** <positive_integer>] [-**state** ( ENABLED | DISABLED )] [-**logstate** ( ENABLED | DISABLED ) [-**ratelimit** <positive_integer>]]

• show ns acl [<aclName>]

To create an extended ACL6 by using the CLI:

At the command prompt, type:

• **add ns acl6** <acl6name> <acl6action> [-**srcIPv6** [<operator>] <srcIPv6Val>] [-**srcPort** [<operator>] <srcPortVal>] [-**destIPv6** [<operator>] <destIPv6Val>] [-**destPort** [<operator>] <destPortVal>] [-**TTL** <positive_integer>] [-**srcMac** <mac_addr>] [(-**protocol** <protocol> [-established]) | -**protocolNumber** <positive_integer>] [-**vlan** <positive_integer>] [-**interface** <interface_name>] [-**icmpType** <positive_integer> [-**icmpCode** <positive_integer>]] [-**priority** <positive_integer>] [-**state** ( ENABLED | DISABLED )]

• show ns acl6 [<aclName>]

To modify an extended ACL by using the CLI:

To modify an extended ACL, type the set ns acl command, the name of the extended ACL, and the parameters to be changed, with their new values.

To modify an extended ACL6 by using the CLI:

To modify an extended ACL6, type the set ns acl6 command, the name of the extended ACL6, and the parameters to be changed, with their new values.

To disable or enable an extended ACL by using the CLI:

At the command prompt, type one of the following commands:

• disable ns acl <aclname>
• enable ns acl <aclname>

To disable or enable an extended ACL6 by using the CLI:

At the command prompt, type one of the following commands:

• disable ns acl6 <aclname>
• enable ns acl6 <aclname>

To apply extended ACLs by using the CLI:

At the command prompt, type:

• apply ns acls

To apply extended ACL6s by using the CLI:

At the command prompt, type:

• apply ns acls6

To renumber the priorities of extended ACLs by using the CLI:

At the command prompt, type:

• renumber ns acls

To renumber the priorities of extended ACL6s by using the CLI:

At the command prompt, type:

• renumber ns acls6

GUI procedures

To configure an extended ACL by using the GUI:

• Navigate to System > Network > ACLs and, on the Extended ACLs tab, add a new extended ACL or edit an existing extended ACL. To enable or disable an existing extended ACL, select it, and then select Enable or Disable from the Action list.

To configure an extended ACL6s by using the GUI:

• Navigate to System > Network > ACLs and, on the Extended ACL6s tab, add a new extended ACL6 or edit an existing extended ACL6. To enable or disable an existing extended ACL6, select it, and then select Enable or Disable from the Action list.

To apply extended ACLs by using the GUI:

• Navigate to System > Network > ACLs and, on the Extended ACLs tab, in the Action list, click Apply.

To apply extended ACL6s by using the GUI:

• Navigate to System > Network > ACLs and, on the Extended ACL6s tab, in the Action list, click Apply.

To renumber the priorities of extended ACLs by using the GUI:

• Navigate to System > Network > ACLs and, on the Extended ACLs tab, in the Action list, click Renumber Priority (s).

To renumber the priorities of extended ACL6s by using the GUI:

• Navigate to System > Network > ACLs and, on the Extended ACL6s tab, in the Action list, click Renumber Priority (s).

Sample Configurations

The following table shows examples of configuring extended ACL rules through the command line interface: ACLs sample configurations.

Logging extended ACLs

You can configure the Citrix ADC to log details for packets that match extended ACLs.

In addition to the ACL name, the logged details include packet-specific information such as the source and destination IP addresses. The information is stored either in the syslog file or in the nslog file, depending on the type of global logging (syslog or nslog) enabled.

Logging must be enabled at both the global level and the ACL level. The global setting takes precedence.

To optimize logging, when multiple packets from the same flow match an ACL, only the first packet’s details are logged, and the counter is incremented for every packet that belongs to the same flow. A flow is defined as a set of packets that have the same values for the source IP address, destination IP address, source port, destination port, and protocol parameters. To avoid flooding of log messages, the Citrix ADC performs internal rate limiting so that packets belonging to the same flow are not repeatedly logged. The total number of different flows that can be logged at any given time is limited to 10,000.

Note: You must apply ACLs after you enable logging.

CLI procedures

To configure extended ACL Logging by using the CLI:

At the command prompt, type the following commands to configure logging and verify the configuration:

• **set ns acl** <aclName> [-**logState** (ENABLED | DISABLED)] [-**rateLimit** <positive_integer>]
• apply acls
• show ns acl [<aclName>]

GUI procedures

To configure extended ACL Logging by using the GUI:

1. Navigate to System > Network > ACLs and, on the Extended ACLs tab, open the extended ACL.
2. Set the following parameters:
   • Log State—Enable or disable logging of events related to the extended ACL rule. The log messages are stored in the configured syslog or auditlog server.
   • Log Rate Limit—Maximum number of log messages to be generated per second. If you set this parameter, you must enable the Log State parameter.

Sample configuration

> set ns acl restrict -logstate ENABLED -ratelimit 120
Warning: ACL modified, apply ACLs to activate change

> apply ns acls
Done
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Logging extended ACL6s

You can configure the Citrix ADC appliance to log details for packets that match an extended ACL6 rule. In addition to the ACL6 name, the logged details include packet-specific information, such as the source and destination IP addresses. The information is stored either in a syslog or nslog file, depending on the type of logging (syslog or nslog) that you have configured in the Citrix ADC appliance.

To optimize logging, when multiple packets from the same flow match an ACL6, only the first packet’s details are logged. The counter is incremented for every other packet that belongs to the same flow. A flow is defined as a set of packets that have the same values for the following parameters:

• Source IP
• Destination IP
• Source port
• Destination port
• Protocol (TCP or UDP)

If an incoming packet is not from the same flow, a new flow is created. The total number of different flows that can be logged at any given time is limited to 10,000.

CLI procedures

To configure logging for an extended ACl6 rule by using the CLI:

• To configure logging while adding the extended ACL6 rule, at the command prompt, type:

  • **add acl6** <acl6Name> <acl6action> [-**logState** (ENABLED | DISABLED)] [-**rateLimit** <positive_integer>]
  • apply acls6
  • show acl6 [<acl6Name>]

• To configure logging for an existing extended ACL6 rule, at the command prompt, type:

  • **set acl6** <acl6Name> [-**logState** (ENABLED | DISABLED)] [-**rateLimit** <positive_integer>]
  • show acl6 [<acl6Name>]
  • apply acls6

GUI procedures

To configure extended ACL6 Logging by using the GUI:

1. Navigate to System > Network > ACLs and, then click the Extended ACL6s tab.
2. Set the following parameters while adding, or modifying an existing extended ACL6 rule.
   • Log State — Enable or disable logging of events related to the extended ACL6s rule. The log messages are stored in the configured syslog or auditlog server.
   • Log Rate Limit—Maximum number of log messages to be generated per second. If you set this parameter, you must enable the Log State parameter.

Sample configuration

> set acl6 ACL6-1 -logstate ENABLED -ratelimit 120
Done

> apply acls6
Done
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Displaying extended ACLs and extended ACL6s statistics

You can display statistics of extended ACLs and ACL6s.

The following table lists the statistics associated with extended ACLs and ACL6s, and their descriptions.

CLI procedures

To display the statistics of all extended ACLs by using the CLI:

At the command prompt, type:

• stat ns acl

To display the statistics of all extended ACL6s by using the CLI:

At the command prompt, type:

• stat ns acl6

GUI procedures

To display the statistics of an extended ACL by using the GUI:

• Navigate to System > Network > ACLs, on the Extended ACLs tab, select the extended ACL, and click Statistics.

To display the statistics of an extended ACL6 by using the GUI:

• Navigate to System > Network > ACLs, on the Extended ACL6s tab, select the extended ACL, and click Statistics.

Stateful ACLs

A stateful ACL rule creates a session when a request matches the rule and allows the resulting responses even if these responses match a deny ACL rule in the Citrix ADC appliance. A stateful ACL offloads the work of creating more ACL rules/forwarding session rules for allowing these specific responses.

Stateful ACLs can be best used in an edge firewall deployment of a Citrix ADC appliance having the following requirements:

• The Citrix ADC appliance must allow requests initiated from internal clients and the related responses from the Internet.
• The appliance must drop the packets from the Internet that are not related to any client connections.

Before you begin

Before you configure stateful ACL rules, note the following points:

• The Citrix ADC appliance supports stateful ACL rules and stateful ACL6 rules.
• In a high availability setup, the sessions for a stateful ACL rule are not synchronized to the secondary node.
• You cannot configure an ACL rule as stateful if the rule is bound to any Citrix ADC NAT configuration. Some examples of Citrix ADC NAT configurations are:
  • RNAT
  • Large Scale NAT (large scale NAT44, DS-Lite, large scale NAT64)
  • NAT64
  • Forwarding session
• You cannot configure an ACL rule as stateful if TTL and Established parameters are set for this ACL rule.
• The sessions created for a stateful ACL rule continue to exist until time out irrespective of the following ACL operations:
  • Remove ACL
  • Disable ACL
  • Clear ACL
• Stateful ACLs are not supported for the following protocols:
  • Active FTP
  • TFTP

Configure stateful IPv4 ACL rules

Configuring a stateful ACL rule consists of enabling the stateful parameter of an ACL rule.

To enable the stateful parameter of an ACL rule by using the CLI:

• To enable the stateful parameter while adding an ACL rule, at the command prompt, type:

  • **add acl** <lname> ALLOW -**stateful** (ENABLED | DISABLED)
  • apply acls
  • show acl <name>

• To enable the stateful parameter of an existing ACL rule, at the command prompt, type:

  • **set acl** <name> -**stateful** (ENABLED | DISABLED)
  • apply acls
  • show acl <name>

To enable the stateful parameter of an ACL rule by using the GUI:

1. Navigate to System > Network > ACLs and, on the Extended ACLs tab.

2. Enable the Stateful parameter while adding, or modifying an existing ACL rule.

Sample configuration

> add acl ACL-1 allow -srciP 1.1.1.1 -stateful Yes

Done

> apply acls

Done

> show acl

1)         Name: ACL-1

    Action: ALLOW                          Hits: 0

    srcIP = 1.1.1.1

    destIP

    srcMac:

    Protocol:

    Vlan:                                 Interface:

    Active Status: ENABLED                 Applied Status: NOTAPPLIED

    Priority: 10                           NAT: NO

    TTL:

    Log Status: DISABLED

    Forward Session: NO

    Stateful: YES
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Configure stateful ACL6 rules

Configuring a stateful ACL6 rule consists of enabling the stateful parameter of an ACL6 rule.

To enable the stateful parameter of an ACL6 rule by using the CLI:

• To enable the stateful parameter while adding an ACL6 rule, at the command prompt, type:

  • **add acl6** <name> ALLOW -stateful ( ENABLED | DISABLD )
  • apply acls6
  • show acl6 <name>

• To enable the stateful parameter of an existing ACL6 rule, at the command prompt, type:

  • **set acl6** <name> -**stateful** ( ENABLED | DISABLED )
  • apply acls6
  • show acl6 <name>

To enable the stateful parameter of an ACL6 rule by using the GUI:

1. Navigate to System > Network > ACLs and, on the Extended ACL6s tab.
2. Enable the Stateful parameter while adding, or modifying an existing ACL6 rule.

Sample configuration

>  add acl6 ACL6-1 allow -srcipv6 1000::1 –stateful Yes

Done

>  apply acls6

Done

> show acl6

1)    Name: ACL6-1

    Action: ALLOW                          Hits: 0

    srcIPv6 = 1000::1

    destIPv6

    srcMac:

    Protocol:

    Vlan:                                 Interface:

    Active Status: ENABLED                 Applied Status: NOTAPPLIED

    Priority: 10                           NAT: NO

    TTL:

    Forward Session: NO

    Stateful: YES
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Dataset based extended ACLs

Many ACLs are required in an enterprise. Configuring and managing many ACLs is difficult and cumbersome when they require frequent changes.

A Citrix ADC appliance supports datasets in extended ACLs. Dataset is an existing feature of a Citrix ADC appliance. A dataset is an array of indexed patterns of types: number (integer), IPv4 address, or IPv6 address.

Dataset support in extended ACLs is useful for creating multiple ACL rules, which require common ACL parameters.

While creating an ACL rule, instead of specifying the common parameters, you can specify a dataset, which includes these common parameters.

Any changes made in the dataset are automatically reflected in the ACL rules that are using this dataset. ACLs with datasets are easier to configure and manage. They are also smaller and easier to read than the conventional ACLs.

Currently, the Citrix ADC appliance supports only the IPv4 address type dataset for extended ACLs.

Before you begin

Before configuring dataset based extended ACL rules, note the following points:

• Make sure that you are familiar with the dataset feature of a Citrix ADC appliance. For more information about datasets, see Pattern sets and data sets.
• The Citrix ADC appliance supports datasets only for IPv4 extended ACLs.
• The Citrix ADC appliance supports only the IPv4 type datasets for extended ACLs.
• The Citrix ADC appliance supports Dataset based extended ACLs for all set ups: standalone, high availability, and cluster.

• For an extended ACL with a range of IP addresses, the Citrix ADC appliance internally creates an extended ACL for each IP address. For example, for an IPv4 dataset based extended ACL with 1000 IPv4 addresses bound to the dataset, the Citrix ADC appliance internally created 1000 extended ACLs.

  • The Citrix ADC appliance supports a maximum of 10K extended ACLs. For an IPv4 dataset based extended ACL with a range of IP addresses bound to the dataset, the Citrix ADC appliance stops creating internal ACLs once the total number of extended ACLs reaches the maximum limit.

  • The following counters are present as part of the extended ACL statistics:

    • ACL count. Total number of ACL rules configured by users.
    • Effective ACL count. Total number of effective ACL rules that the Citrix ADC appliance configures internally.

    For more information, see Displaying extended ACL and extended ACL6s Statistics.

• The Citrix ADC appliance does not support set and unset operations for associating/dissociating datasets with the parameters of an extended ACL. You can set the ACL parameters to a dataset only during the add operation.

Configure dataset based extended ACLs

Configuring a dataset based extended ACL rule consists of the following tasks:

• Add a dataset. A dataset is an array of indexed patterns of types: number (integer), IPv4 address, or IPv6 address. In this task, you create a type of dataset, for example, a dataset of type IPv4.

• Bind values to the dataset. Specify a value or a range of values to the dataset. The specified values must be of the same type as the dataset type. For example, you can specify an IPv4 address or a range of IPv4 addresses to the dataset of type IPv4.

• Add an extended ACL and set ACL paramters to the dataset. Add an extended ACL and set the required ACL parameters to the dataset. This setting results in the parameters set to the values specified in the dataset.

• Apply extended ACLs. Apply the ACLs to activate any new or modified extended ACLs.

To add a policy dataset by using the CLI:

At the command prompt, type:

• add policy dataset <name> <type>
• show policy dataset

To bind a pattern to the data set by using the CLI:

At the command prompt, type:

• bind policy dataset <name> <value> [-endRange <string>]
• show policy dataset

To add an extended ACL and set the ACL paramters to the dataset by using the CLI:

At the command prompt, type:

• add ns acl <aclname> <aclaction> [-srcIP [<operator>] <srcIPVal>] [-srcPort [<operator>] <srcPortVal>] [-destIP [<operator>] <destIPVal>] [-destPort [<operator>] <destPortVal>] …
• show acls

To apply extended ACLs by using the CLI:

At the command prompt, type:

• apply acls

Sample configuration

In the following sample configuration of a dataset based extended ACL, an IPv4 dataset DATASET-ACL-1 is created. Two IPv4 addresses: 192.0.2.30 and 192.0.2.60, and two IPv4 address ranges: (198.51.100.15 - 45) and (203.0.113.60-90) are bound to DATASET-ACL-1. DATASET-ACL-1 is then specified to the srcIP and destIP parameters of the extended ACL ACL-1.

add policy dataset DATASET-ACL-1 IPV4

bind dataset DATASET-ACL-1 192.0.2.30

bind dataset DATASET-ACL-1 192.0.2.60

bind dataset DATASET-ACL-1 198.51.100.15 -endrange 198.51.100.45

bind dataset DATASET-ACL-1 203.0.113.60 -endrange 203.0.113.90

add ns acl ACL-1 ALLOW -srcIP DATASET-ACL-1 -destIP DATASET-ACL-1

apply acls
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