Usage Guidelines

You can create up to 16 service chains in a Cisco Catalyst SD-WAN network.

Usage Guidelines

• This command is available after you create a service chain with the service-chain command.

• Unless you require all BFD sessions to be brought down when a service chain goes down, we recommend that this command not be used to prevent the unintended disruption of BFD.

Usage Guidelines

This command is available after you create a service chain with the service-chain command.

Usage Guidelines

• This command is available after you create a service chain with the service-chain command.

• Because a service chain is enabled by default, you do not need to use this command to enable s service chain unless you have first used this command to disable the service chain.

• This command is useful when you want to create a service chain but are not ready for it to become active. In this situation, create the service chain and use this command disable it. You enable the service chain later when you want it to be active.

Usage Guidelines

• This command is available after you create a service chain with the service-chain command.

• All services in the service chain must be accessible through the VPN that you specify.

• This command does not have a no form.

Usage Guidelines

• This command is available after you specify the name of the VPN in which all services in the service chain are to be hosted with the service-chain-vrf command.

• A service chain must have at least one service, so you cannot remove all services from a service chain.

• Using a service-type name that corresponds to a service provides a convenient way for you to identify a service in a service chain. However, any service can be connected to any service-type name.

• Configure the following service-parameters for each service type:

  • sequence sequence-number

    Relative position of the service type in the service chain, which is the order in which the services in the service chain are applied to traffic. Services are applied from the lowest sequence-number value to the highest, and this value can be any number from 1 through 65535.

    We recommend that you leave gaps between sequence-number values so that you can easily add services to a service chain if needed. For example, if you create a service chain with two service types, assign the service types sequence numbers of 100 and 200. The service type with a sequence-number of 100 is applied to traffic first. If you then want add a third sequence but want it to be applied in the second position, you can assign it a sequence number of 150 (or any value between 100 and 200).

  • service-transport-ha-pair value {active | [backup ]} {tx | [rx ]} {{ipv4 | ipv6 | tunnel-interface } address-or-number } {interface port-number interface-name } [endpoint-tracker name ]

    Specifies the number of high availability pairs (active and optionally backup interfaces) that can be configured for forwarding traffic for the service and configures these high availability pairs.

    value is the number of high availability pairs and can be a number 1 through 8. The high availability pairs can use IPv4, IPv6, or tunneled interfaces, depending on how the service is attached to a router. For dual stack connectivity, configure up to four IPv4 and four IPv6 high availability pairs.

    active specifies an active interface, and backup specifies a backup interface.

    tx specifies that packets are sent on the interface, and rx specifies that packets are received on the interface. If rx is not specified, packets are both sent and received on the interface.

    ipv4 , ipv6 , or tunnel-interface specify the method by which the service is attached to a router.

    For the IPv4 or IPv6 attachment method address-or-number is the IP address of the service to be attached to the service type. For the tunnel interface attachment method, address-or-number is the tunnel number for the service to be attached to the service type.

    interface is the type of interface that is used to connect to the service, port-number is the number of the port on which the service communicates, and interface-name is the name of the interface. interface can be any of the following:

    • Ethernet

    • FastEthernet

    • FiveGigabitEthernet

    • FortyGigabitEthernet

    • GigabitEthernet

    • HundredGigabitEthernet

    • TenGigabitEthernet

    • TwentyFiveGigE

    • TwoGigabitEthernet

  • endpoint-tracker name

    By default, tracking is enabled for the service chain, and the tracker uses the tx and rx IP addresses of a service to track the service. Use this endpoint-tracker option if you want to track the service using other IP addresses. name is the name of the tracker that defines the IP address to use. You can configure an endpoint tracker for the tx interface, the rx interface, or both interfaces. If you use this option, ensure that routing for this tracker is configured appropriately in your deployment.

    Note

    For any interface, reachability for only one IPv4 address and one IPv6 address can be tracked. For example, if a high availability pair is configured with the service IP address of 10.1.1.1 on the GigabitEthernet3 interface, another service IP address cannot be tracked on GigabitEthernet3. Similarly, only one IPv4 address and one IPv6 address can be tracked for a dual stack interface.

Usage Guidelines

• The service command must be configured before you can configure a trust posture with this command. See service.

• The trust posture configuration of each high availability pair in a service chain must be the same. By default, the trust posture for each interface in each high availability pair is trusted. However, if one interface in a high availability pair has a trust posture of trusted and the other interface has a trust posture of untrusted, all high availability pairs in the service chain must be configured in this way.

Usage Guidelines

• This command is available after you create a service chain with the service-chain command.

• Tracking generates an alert if a service goes down. If tracking is not enabled, you can still check the state of the Cisco Catalyst SD-WAN interface where a service is deployed to determine whether the service is up or down. For instructions, see ICMP Endpoint Tracker for NAT DIA.