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Multihoming an IP-Connected End System Design and Implementation

For an overview of multihoming an IP-connected end system, see the Multihoming Support for IP-Connected End Systems section in Data Center Fabric Blueprint Architecture Components.

Figure 1 illustrates the multihomed IP-connected end system—in this procedure, the end system is an IP-connected server—that is enabled using this procedure:

Figure 1: Multihomed IP-Connected End System ExampleMultihomed IP-Connected End System Example

This configuration uses one VLAN per leaf device access interface. See Configuring a Layer 3 Subinterface (CLI Procedure) to enable VLAN tagging if your setup requires multiple VLANs per leaf device access interface.

Configuring the End System-Facing Interfaces on a Leaf Device

To configure the IP address of each end system-facing interface on the leaf devices:

  1. Configure an IP address on each end system-facing leaf device interface, and put the interface in a VRF.

    Leaf 10:


    The VRF_5 routing instance was configured earlier in this guide with this EBGP configuration. See Routed Overlay Design and Implementation.

    Leaf 11:

    Leaf 12:


    The VRF_5 routing instance was not explicitly configured for Leaf 11 and 12 earlier in this guide.

    To configure the VRF_5 routing instance to run on Leaf 11 and 12, repeat the procedures in Routed Overlay Design and Implementation for these leaf devices. Be sure to configure a unique route distinguisher for each route to ensure that each leaf device route is treated as a unique route by the route reflectors.

  2. After committing the configuration, confirm that each link is up and that the IP address is properly assigned.

    Sample output from Leaf 10 only is provided in this step.

    Leaf 10:

Configuring EBGP Between the Leaf Device and the IP-Connected End System

EBGP—which is already used in this reference design to pass routes between spine and leaf devices in the underlay network—is also used in this reference design to pass routes between the IP-connected server and a leaf device.


Other routing protocols can be used to pass routes between an IP-connected end system and the leaf device. However this is not recommended.

To configure EBGP between a leaf device and an IP-connected end system:

  1. Configure EBGP in a VRF routing instance.

    Leaf 10:

  2. Repeat this procedure on all leaf device interfaces that are multihomed to the IP-connected end system.

    Leaf 11:

    Leaf 12:

  3. After committing the configurations, confirm that BGP is operational.

    A sample of this verification procedure on Leaf 10 is provided below.

    Leaf 10:

Multihoming an IP-Connected End System—Release History

Table 1 provides a history of all of the features in this section and their support within this reference design.

Table 1: Multihoming IP-Connected End Systems Release History




QFX10002-60C and QFX5120-32C switches running Junos OS Release 19.1R2 and later releases in the same release train support all features documented in this section.


All devices in the reference design that support Junos OS Release 17.3R3-S1 and later releases in the same release train also support all features documented in this section.