Routing Configuration Guide, Cisco Catalyst SD-WAN Releases 17.x

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OMP vRoute advertisement optimization using system path

Updated: February 6, 2026

Overview

Describes a memory-saving feature that flattens advertisements from a per-TLOC basis to a per-System IP basis.

Traditionally, OMP on the Cisco SD-WAN Controller creates a vRoute advertisement (RIB-Out) for each TLOC (Transport Locators) for every vRoute NLRI prefix it learns from a device. If a device has multiple TLOCs, the number of advertisements increases. When all TLOC paths are treated equally in the control plane, the advertisements become duplicates. This duplication consumes excessive memory on the Cisco SD-WAN Controller. As a result, devices can experience out-of-memory issues, reboots, slower network convergence, and reduced SD-WAN scalability.

The OMP RIB-Out optimization using the TLOC path feature changes OMP behavior. Instead of creating vRoute RIB-Outs on a per-TLOC basis, the system now generates them based on each SysIP (System IP). This process significantly reduces memory consumption on Cisco SD-WAN Controllers, increases scalability, and improves convergence performance in large-scale SD-WAN deployments.

Benefits

  1. Flattened RIB-Outs: Instead of sending multiple RIB-Outs for each TLOC associated with a prefix, only one flat RIB-Out per system IP is sent to peers.

  2. Memory Reduction: This change drastically reduces the number of RIB-Outs generated. The memory consumption per prefix decreases by a factor of N, where N is the number of source TLOCs. For example, when a prefix with two TLOCs sent to two Cisco SD-WAN Controller peers, the system generates two RIB-Outs instead of four.

  3. Scope: This optimization applies only to vRoute IPv4 and IPv6 address families in Cisco IOS XE Catalyst SD-WAN Release 17.18.2.

  4. Backward Compatibility:

    • The feature introduces a new OMP protocol version (version 4) for peers understanding the optimization, while older peers (version 3) will continue to use the legacy per-TLOC format.

    • New Cisco SD-WAN Controllers and Cisco IOS XE Catalyst SD-WAN devices can communicate with old devices by dynamically adjusting the RIB-Out format (sending legacy per-TLOC to old peers).

    • Control policies that differentiate traffic based on TLOC, color, or service attributes disable this optimization for the affected routes. The system falls back to the legacy per-TLOC RIB-Outs to ensure policy adherence.