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assisted-replication (Deterministic AR Replicator Policy Actions)

Syntax

Hierarchy Level

Description

Configure routing policy actions in a routing policy for an assisted replication (AR) leaf device to deterministically steer multicast flows to specific AR replicator devices in an EVPN network.

Assign the routing policy to an EVPN instance on the AR leaf device using the deterministic-ar-policy statement at the [edit routing-instances name protocols evpn assisted-replication leaf] hierarchy level.

Note:

AR is a multicast traffic flow optimization feature where an ingress leaf device sends one copy of a multicast stream to another device called an AR replicator in the EVPN network. AR replicators are devices that can efficiently handle replicating and forwarding multicast streams to the other multicast receivers in the network. See Assisted Replication Multicast Optimization in EVPN Networks for details on how AR works and how to configure AR leaf and AR replicator devices.

When you assign routing policies with these actions on an AR leaf device, you control how the device load-balances multicast flows among the available AR replicator devices. The AR leaf device directs flows that match the routing policy's from conditions to the AR replicator device or devices you specify with this statement in the policy's then clause.

In the policy from clause, you can specify to match an IGMPv2 or MLDv1 multicast flow with either or both of the following parameters:

  • A multicast group address.

  • A bridge domain or VLAN-mapped virtual network identifier (VNI).

You can set match conditions for a source-specific multicast (SSM) IGMPv3 or MLDv2 multicast flow with any combination of the following parameters:

  • A multicast group address.

  • A bridge domain or VLAN-mapped virtual network identifier (VNI).

  • A multicast source device address.

When you configure the then clause of the policy with the assisted-replication action statement we describe on this page, you must specify the replicator-ip option with the address of an AR replicator in the network.

You can configure the policy to direct matching flows strictly to that preferred AR replicator by including the strict option, which we call strict mode. In strict mode, if the preferred AR replicator goes down, the leaf device drops the matching traffic (even if the network has other available AR replicators).

By default, if you don't configure the strict option, the AR leaf device uses loose mode. In loose mode, you can include the fallback-replicator-ip option to configure the AR leaf device to use a fallback AR replicator if the preferred AR replicator goes down.

Also, consider the following cases in loose mode:

  • You specify a fallback replicator, but both the preferred AR replicator and the fallback replicator go down.

  • You don't specify a fallback replicator, and the preferred AR replicator goes down.

In those cases, if the AR leaf device detects other available AR replicators in the network, the device uses the default AR replicator load balancing method to distribute multicast traffic among the remaining available AR replicators.

Otherwise, if the AR leaf device doesn't detect any other AR replicators in the network, the device defaults to ingress replication behavior (replicates and forwards the multicast traffic itself to any interested receivers in the EVPN core).

Options

replicator-ip replicator-ip

(Required) Set a preferred AR replicator to which the AR leaf device directs the multicast flows that match the conditions in the policy statement's from clause.

The replicator-ip parameter is the secondary loopback address you assign for the AR replicator function when you configure a device as an AR replicator. For example:

See the replicator statement and the instructions in Configure an AR Replicator Device.
fallback-replicator-ip fallback-replicator-ip

(Optional) Set a fallback AR replicator to which the AR leaf device redirects the matching flows if the preferred AR replicator goes down.

The fallback-replicator-ip parameter is the AR replicator secondary loopback address of the device you want to use as the fallback device, similar to the address you specify with the replicator-ip option explained above.
strict

(Optional) Strictly use only the AR replicator(s) you specify with the replicator-ip option. The device doesn't redirect any flows to any other AR replicator if the specified AR replicator goes down; it drops any traffic the policy matches.

Note:

The strict and fallback-replicator-ip options are mutually exclusive.

Required Privilege Level

routing—To view this statement in the configuration.

routing-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Evolved Release 23.4R2.

Related Documentation