Skip to main content
Cisco SD-WAN
Support
Product Documentation
Viptela Documentation

Configuring Localized Data Policy for IPv6

This article provides procedures for configuring IPv6 localized data policy This type of data policy is called access lists, or ACLs. You can provision simple access lists that filter traffic based on IP header fields. You also use access lists to apply mirroring and policing to data packets. 

For IPv6, you can apply access lists only to interfaces in the transport VPN, VPN 0.

In vManage NMS, you configure localized data policy from the Configuration ► Policies screen, using a policy configuration wizard. In the CLI you configure these policies on the vEdge router.

Configuration Components

An access list consists of a sequences of match–action pairs that are evaluated in order, from lowest sequence number to highest sequence number. When a packet matches one of the match conditions, the associated action is taken and policy evaluation on that packets stops. Keep this in mind as you design your policies to ensure that the desired actions are taken on the items subject to policy.

If a packet matches no parameters in any of the sequences in the policy configuration, it is, by default, dropped.

To create an IPv6 access list, you include the following components in the configuration on a vEdge router:

Component

Description

vManage Configuration

CLI 

Logging Frequency If you configure a logging action, log only a sample of data packet headers instead of all of them. Configuration ► Policies ► Localized Policy ► Add Policy ► Policy Overview ► Log Frequency policy logging-frequency

Mirroring and policing parameters

Parameters and rules required to configure traffic mirroring and policing. For mirroring, you configure the addresses of the source of the packets to be mirrored and the mirroring site. (You can mirror only unicast traffic.) For policing, you define transmission parameters.

Configuration ► Policies ► Localized Policy ► Add Policy ► Create Groups of Interest

or

Configuration ► Policies ► Custom Options ► Localized Policy ► Create Groups of Interest

policy mirror

policy policer

Access list instance

Container for an access list.

Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists

or

Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control Lists

policy ipv6 access-list

Numbered sequences of match–action pairs

Sequences establish the order in which the policy components are applied.

Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists

or

Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control Lists

policy ipv6 access-list sequence

Match parameters

Conditions that packets must match to be considered for a data policy.

Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists

or

Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control Lists

policy ipv6 access-list sequence match

Actions

Whether to accept or reject matching packets, and how to process matching items.

Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists

or

Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control Lists

policy ipv6 access-list sequence action

Default action

Action to take if a packet matches none of the match parameters in any of the sequences. By default, nonmatching packets are dropped.

Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists

or

Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control Lists

policy ipv6 access-list default-action

Application of access lists

For an access list to take effect, you apply it an interface.

Configuration  ► Templates ► Feature ►
VPN Interface Bridge, VPN Interface Cellular, VPN Interface Ethernet, VPN Interface GRE, VPN Interface PPP, or VPN Interface PPP Ethernet

vpn 0 interface ipv6 access-list

General vManage Configuration Procedure

To configure IPv6 localized data policy, use the vManage policy configuration wizard. The wizard is a UI policy builder that consists of five screens, and you use four of them to configure IPv6 localized policy components:

  • Groups of Interest, also called lists—Create data prefix lists and mirroring and policer parameters that group together related items and that you call in the match or action components of a policy.
  • Access Control Lists—Define the match and action conditions of ACLs.
  • Route Policies—Define the match and action conditions of route policies.
  • Policy Settings—Define additional policy settings, including the frequency for logging policy-related packet headers.

You configure some or all these components depending on the specific policy you are creating. To skip a component, click the Next button at the bottom of the screen. To return to a component, click the Back button at the bottom of the screen.

Start the Policy Configuration Wizard

To start the policy configuration wizard:

  1. In vManage NMS, select the Configure ► Policies screen. When you first open this screen, the Centralized Policy tab is selected by default.
  2. Select the Localized Policy tab.
  3. Click Add Policy. The policy configuration wizard opens, and the Create Groups of Interest screen is displayed.

Create Groups of Interest

To create lists of groups to use in localized data policy:

  1. Start the policy configuration wizard as explained above.
  2. Create new lists, as described in the following table:
List Type Procedure
Mirror
  1. In the left bar, click TLOC.
  2. Click New TLOC List. The TLOC List popup displays.
  3. Enter a name for the list.
  4. In the TLOC IP field, enter the system IP address for the TLOC.
  5. In the Color field, select the TLOC's color.
  6. In the Encap field, select the encapsulation type.
  7. In the Preference field, optionally select a preference to associate with the TLOC.
  8. Click Add TLOC to add another TLOC to the list.
  9. Click Save.
Policer
  1. In the left bar, click VPN.
  2. Click New VPN List.
  3. Enter a name for the list.
  4. In the Add VPN field, enter one or more VPN IDs separated by commas.
  5. Click Add.
  1. Click Next to move to Configure Forwarding Classes/QoS in the wizard. For IPv6 localized data policy, you cannot configure QoS.
  2. Click Next to move to Configure Access Lists in the wizard.

Configure ACLs

To configure access control lists (ACLs):

  1. To create a new IPv6 ACL, click the Add Access Control List Policy drop-down. Then select Add IPv6 ACL Policy.
  2. Enter a name and description for the ACL.
  3. In the left pane, click Add ACL Sequence. An Access Control List box is displayed in the left pane.
  4. Double-click the Access Control List box, and type a name for the ACL.
  5. In the right pane, click Add Sequence Rule to create a single sequence in the ACL. The Match tab is selected by default.
  6. Click a match condition.
  7. On the left, enter the values for the match condition.
  8. On the right enter the action or actions to take if the policy matches.
  9. Repeat Steps 6 through 8 to add match–action pairs to the ACL.
  10. To rearrange match–action pairs in the ACL, in the right pane drag them to the desired position.
  11. To remove a match–action pair from the ACL, click the X in the upper right of the condition.
  12. Click Save Match and Actions to save a sequence rule.
  13. To rearrange sequence rules in an ACL, in the left pane drag the rules to the desired position.
  14. To copy, delete, or rename an ACL sequence rule, in the left pane, click More Options next to the rule's name and select the desired option.
  15. If no packets match any of the ACL sequence rules, the default action is to drop the packets. To change the default action:
    1. Click Default Action in the left pane.
    2. Click the Pencil icon.
    3. Change the default action to Accept.
    4. Click Save Match and Actions.
  16. Click Next to move to Configure Route Policy in the wizard. Click Next to move to the Policy Overview screen.

Configure Policy Settings

To configure policy settings, in the Policy Overview screen:

  1. Enter a name and description for the route policy.
  2. To log the headers of all packets that are dropped because they do not match a service configured by an Allow Service parameter on a tunnel interface, click Implicit ACL Logging.
  3. To configure how often packets flows are logged, click Log Frequency. Packet flows are those that match an access list (ACL), a cflowd flow, or an application-aware routing flow.
  4. Click Preview to view the full policy in CLI format.
  5. Click Save Policy.

Apply a Localized Data Policy in a Device Template

  1. n vManage NMS, select the Configuration ► Templates screen.
  2. If you are creating a new device template:
    1. In the Device tab, click Create Template.
    2. From the Create Template drop-down, select From Feature Template.
    3. From the Device Model drop-down, select one of the vEdge devices.
    4. In the Template Name field, enter a name for the device template. This field is mandatory and can contain only uppercase and lowercase letters, the digits 0 through 9, hyphens (–), and underscores (_). It cannot contain spaces or any other characters.
    5. In the Description field, enter a description for the device template. This field is mandatory, and it can contain any characters and spaces.
    6. Continue with Step 4.
  3. If you are editing an existing device template:
    1. In the Device tab, click the More Actions icon to the right of the desired template, and click the pencil icon.
    2. Click the Additional Templates tab. The screen scrolls to the Additional Templates section.
    3. From the Policy drop-down, select the name of a policy that you have configured.
  4. Click the Additional Templates tab located directly beneath the Description field. The screen scrolls to the Additional Templates section.
  5. From the Policy drop-down, select the name of the policy you configured in the above procedure.
  6. Click Create (for a new template) or Update (for an existing template).

General CLI Configuration Procedure

Following are the high-level steps for configuring an access list using the CLI:

  1. Define mirroring parameters (for unicast traffic only):​
  2. vEdge(config)# policy mirror mirror-name
    vEdge(config-mirror)# remote-dest ip-address source ip-address
  3. Define policing parameters:​
    vEdge(config)# policy policer policer-name
    vEdgeconfig-policer)# rate bandwidth
    vEdge(config-policer)# burst bytes
    vEdge(config-policer)# exceed action
  4. Create an access list instance:​
    vEdge(config)# policy ipv6 access-list list-name
  5. Create a series of match–action pair sequences:
    vEdge(config-ipv6-access-list)# sequence number
    vEdge(config-sequence)#

    The match–action pairs are evaluated in order, by sequence number, starting with the lowest numbered pair and ending when the route matches the conditions in one of the pairs. Or if no match occurs, the default action is taken (either rejecting the route or accepting it as is).
  6. Define match parameters for packets:
    vEdge(config-sequence-number)# match match-parameter
  7. Define actions to take when a match occurs:
    vEdge(config-sequence)# action drop
    vEdge(config-sequence)# action count counter-name
    vEdge(config-sequence)# action log
    vEdge(config-sequence)# action accept class class-name
    vEdge(config-sequence)# action accept mirror mirror-name
    vEdge(config-sequence)# action accept policer policer-name
  8. Create additional numbered sequences of match–action pairs within the access list, as needed.
  9. If a packet does not match any of the conditions in one of the sequences, it is rejected by default. If you want nonmatching packets to be accepted, configure the default action for the access list:
    vEdge(config-policy-name)# default-action accept
  10. Apply the access list to an interface:
    vEdge(config)# vpn vpn-id interface interface-name
    vEdge(config-interface)# ipv6 access-list list-name (in | out)

    Applying the access list in the inbound direction (in) affects packets being received on the interface. Applying it in the outbound direction (out) affects packets being transmitted on the interface.

Structural Components of Configuration for Access Lists

Following are the structural components required to configure access lists. Each one is explained in more detail in the sections below.

policy
  implicit-acl-logging
  log-frequency number
  mirror mirror-name
    remote-dest ip-address source ip-address
  policer policer-name
    rate bandwidth
    burst bytes
    exceed action
policy ipv6
  access-list list-name
    sequence number
      match
        match-parameters
      action
        drop
        count counter-name
        log
        accept
          class class-name 
          mirror mirror-name
          policer policer-name
    default-action
      (accept | drop)
vpn vpn-id
  interface interface-name
    ipv6 access-list list-name (in | out)

Logging Parameters

If you configure a logging action in a data policy, by default, the vEdge router logs all data packet headers to a syslog file. To log only a sample of the data packet headers:

vEdge(config)# policy log-frequency number

number specifies how often to to log packet headers. The default value is 1000. number can be an integer., and the software rounds the value down to the nearest power of 2. So for example, with the default value of 1000, the logging frequency is rounded down to 512, so every 512th packet is logged.

You can log the headers of all packets that are dropped because they do not match a service configured with an allow-service command. You can use these logs for security purposes, for example, to monitor the flows that are being directed to a WAN interface and to determine, in the case of a DDoS attack, which IP addresses to block.

vEdge(config)# policy implicit-acl-logging

When you enable implicit ACL logging, by default, the headers of all dropped packets are logged. It is recommended that you configure a limit to the number of packets logged with the log-frequency command.

In vManage NMS:

  • Configuration ► Policies ► Localized Policy ► Add Policy ► Policy Overview ► Log Frequency field
  • Configuration ► Policies ► Localized Policy ► Add Policy ► Policy Overview ► Implicit ACL Logging field

Mirroring Parameters

To configure mirroring parameters, define the remote destination to which to mirror the packets, and define the source of the packets:

vEdge(config)# policy mirror mirror-name
vEdge(config-mirror)# remote-dest ip-address source ip-address

In vManage NMS:

  • Configuration ► Policies ► Localized Policy ► Add Policy ► Create Groups of Interest ► Mirror ► New Mirror List
  • Configuration ► Policies ► Custom Options ► Localized Policy ► Lists ► Mirror ► New Mirror List

Policer Parameters

To configure policing parameters, create a policer that specifies the maximum bandwidth and burst rate for traffic on an interface, and how to handle traffic that exceeds these values:

vEdge(config)# policy policer policer-name
vEdge(config-policer)# rate bps
vEdge(config-policer)# burst bytes
vEdge(config-policer)# exceed action

rate is the maximum traffic rate. It can be a value from 8 through 10000000 bits per second.

burst is the maximum traffic burst size. It can be a value from 15000 to 1000000 bytes

exceed is the action to take when the burst size or traffic rate is exceeded. action can be drop (the default) or remark. The drop action is equivalent to setting the packet loss priority (PLP) bit to low. The remark action sets the PLP bit to high. In centralized data policy, access lists, and application-aware routing policy, you can match the PLP with the match plp option.

In vManage NMS:

  • Configuration ► Policies ► Localized Policy ► Add Policy ► Create Groups of Interest ► Policer ► New Policer List
  • Configuration ► Policies ► Custom Options ► Localized Policy ► Lists ► Policer ► New Policer List

Sequences

An access list contains sequences of match–action pairs. The sequences are numbered to set the order in which a packet is analyzed by the match–action pairs in the access lists. You configure sequences with the policy ipv6 access-list sequence command.

Each sequence in an access list can contain one match command and one action command.

In vManage NMS:

  • Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists ► Add Access Control List Policy ► Add ACL Sequence
  • Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control List Policy ► Add Access Control List Policy ► Add ACL Sequence

Match Parameters

Access lists can match IP prefixes and fields in the IP headers. You configure the match parameters under the policy access-list sequence match command.

Each sequence in an access-list must contain one match command.

For access lists, you can match these parameters:

Description

Command

Value or Range

Destination port number.

destination-port number

0 through 65535; specify a single port number, a list of port numbers (with numbers separated by a space), or a range of port numbers (with the two numbers separated with a hyphen [-])

Next header protocol

next-header number

0 through 255, corresponding to an Internet Protocol number

Packet length packet-length number Length of the packet. number can be from 0 through 65535. Specify a single length, a list of lengths (with numbers separated by a space), or a range of lengths (with the two numbers separated with a hyphen [-])
Packet loss priority (PLP) plp (high | low)
By default, packets have a PLP value of low. To set the PLP value to high, apply a policer that includes the exceed remark option.

Source port number.

source-portaddress

0 through 65535; specify a single port number, a list of port numbers (with numbers separated by a space), or a range of port numbers (with the two numbers separated with a hyphen [-])

TCP flag

tcp flag

syn

Traffic class traffic-class value 0 through 63

In vManage NMS:

  • Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists ► Add Access Control List Policy ► Add ACL Sequence ► Add Sequence Rule ► Match
  • Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control List Policy ► Add Access Control List Policy ► Add ACL Sequence ► Add Sequence Rule ► Match

Action Parameters

When a packet matches the conditions in the match portion of an access list, the packet can be accepted or dropped, and it can be counted. Then, you can classify, mirror, or police accepted packets. You configure the actions parameters with the policy access-list sequence action command.

Each sequence in an access list can contain one action command.

In the action, you first specify whether to accept or drop a matching data packet, and whether to count it:

Description

Command

Value or Range

Accept the packet. An accepted packet is eligible to be modified by the additional parameters configured in the action portion of the access list.

accept

Count the accepted or dropped packets.

count counter-name

Name of a counter. To display counter information, use the show ipv6 policy access-lists counters command on the vEdge router.

Discard the packet. This is the default action.

drop

Log the packet headers into system logging (syslog) files.

In addition to logging the packet headers, a syslog message is generated the first time a packet header is logged and then every 5 minutes thereafter, as long as the flow is active.

log To display logging information, use the show app log flow-all and show app log flows command on the vEdge router.

For a packet that is accepted, the following actions can be configured:

Description

Command

Value or Range

Mirror the packet.

mirror mirror-name

Name of mirror defined with a policy mirror command.

Police the packet.

police policer-name

Name of a policer defined with a policy policer command.

Set the packet's DSCP value.

set traffic-class value

0 through 63.

In vManage NMS:

  • Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists ► Add Access Control List Policy ► Add ACL Sequence ► Add Sequence Rule ► Action
  • Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control List Policy ► Add Access Control List Policy ► Add ACL Sequence ► Add Sequence Rule ► Action

Default Action

If a packet being evaluated does not match any of the match conditions in a access list, a default action is applied to this packet. By default, the packet is dropped. To modify this behavior, include the access-list ipv6 default-action accept command in the access list.

In vManage NMS:

  • Configuration ► Policies ► Localized Policy ► Add Policy ► Configure Access Control Lists ► Default Action
  • Configuration ► Policies ► Custom Options ► Localized Policy ► Access Control List Policy ► Default Action

Applying Access Lists

For an access list to take effect, you must apply it to a tunnel interface in VPN 0:

vEdge(config)# vpn 0 interface interface-name
vEdge(config-interface)# ipv6 access-list list-name (in | out)

Applying the policy in the inbound direction (in) affects prefixes being received on the interface. Applying it in the outbound direction (out) affects prefixes being transmitted on the interface.

In vManage NMS:

  • Configuration ► Templates ► VPN Interface Bridge
  • Configuration ► Templates ► VPN Interface Cellular
  • Configuration ► Templates ► VPN Interface Ethernet
  • Configuration ► Templates ► VPN Interface GRE
  • Configuration ► Templates ► VPN Interface PPP
  • Configuration ► Templates ► VPN Interface PPP Ethernet

Interaction between Explicit and Implicit Access Lists

Access lists that you configure through localized data policy using the policy access-list command are called explicit ACLs. You can apply explicit ACLs to any interface in any VPN on the router.

The router's tunnel interfaces in VPN 0 also have implicit ACLs, which are also referred to as services. Some services are enabled by default on the tunnel interface, and are in effect unless you disable them. Through configuration, you can also enable other services. You configure and modify implicit ACLs with the allow-service command:

vEdge(config)# vpn 0
vEdge(config-vpn)# interface interface-name
vEdge(config-interface)# tunnel-interface
vEdge(config-tunnel-interface)# allow-service service-name
vEdge(config-tunnel-interface)# no allow-service service-name

On vEdge routers, the following services are enabled by default: DHCP (for DHCPv4 and DHCPv6), DNS, and ICMP. These three services allow the tunnel interface to accept DHCP, DNS, and ICMP packets. You can also enable services for BGP, Netconf, NTP, OSPF, SSHD, and STUN.

When data traffic matches both an explicit ACL and an implicit ACL, how the packets are handled depends on the ACL configuration. Specifically, it depends on:

  • Whether the implicit ACL is configured as allow (allow-service allow-service) or deny (no allow-service service-name). Allowing a service in an implicit ACL is the same as specifying the accept action in an explicit ACL, and a service that is not allowed in an implicit ACL is the same as specifying the drop action in an explicit ACL
  • Whether, in an explicit ACL, the accept or deny action is configured in a policy sequence or in the default action.

The following table explains how traffic matching both an implicit and an explicit ACL is handled:

Implicit ACL Explicit ACL: Sequence Explicit ACL: Default Result
Allow (accept) Deny (drop) Deny (drop)
Allow (accept) Deny (drop) Allow (accept)
Deny (drop) Allow (accept) Allow (accept)
Deny (drop) Allow (accept) Deny (drop)
  • Was this article helpful?