Configuring Floating L3Outs

Configuring Floating L3Outs

In this section we are going to cover the specific configuration steps required to leverage the Floating L3Out functionality. The different sections below will discuss Software and Hardware requirements, the deployment of Floating L3Outs with external devices part of a VMM or a physical domain, the specific configuration required to avoid sub-optimal traffic path toward the external destination and how to leverage multiple equal cost path for this type of communication.

Software Requirements

  • Floating L3Out with VMM domain requires Cisco Application Policy Infrastructure Controller (APIC) Release 4.2(1) or later.

  • Floating L3Out with physical domain requires Cisco APIC Release 5.0(1) or later.

  • Avoiding a suboptimal path requires the following Cisco APIC Releases:

    • If the next-hop for the external prefix is the directly attached IP:

      • Next-hop propagation with BGP requires Cisco APIC Release 5.0(1) or later.

      • Next-hop propagation with OSPF and static route requires Cisco APIC Release 5.2(1) or later.

    • If the next-hop for the external prefixis not the directly attached IP but instead a loopback address (multi-protocol recursive route resolution), Cisco APIC Release 5.2(1) or later is required.

Hardware Requirements

Ensure that you have the correct leaf switches. Floating L3Out does not support the following top-of-rack switches:

  • Cisco Nexus 9332PQ

  • Cisco Nexus 9372PX

  • Cisco Nexus 9372TX

  • Cisco Nexus 9396PX

  • Cisco Nexus 9396TX

  • Cisco Nexus 93120TX

  • Cisco Nexus 93128TX

  • Cisco Nexus 9372PX-E

  • Cisco Nexus 9372TX-E

Floating L3Out mandates the use of generation-2 leaf switches as anchor and non-anchor nodes. The generation-1 switches listed above cannot be configured as anchor or non-anchor nodes. However, you can use a generation-1 switch as a non-border leaf or a compute leaf switch where floating L3Out is not provisioned.

Workflow for Configuring Floating L3Out

This section provides a high-level description of the tasks that you must perform to configure a floating Layer 3 outside network connection (L3Out) when using a VMware vSwitch Distributed Switch (VDS) or a physical domain.