Cisco Catalyst SD-WAN Policies Configuration Guide, Releases 26.x and Later

Restrictions for packet duplication

Updated: April 24, 2026

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Outlines limitations and constraints for packet duplication functionality on network devices.

Consider these restrictions when implementing packet duplication:

Packet duplication interop along with forward error correction (FEC) and TCP optimization on Cisco IOS XE Catalyst SD-WAN devices is not supported between Cisco IOS XE Release 16.x and Cisco IOS XE Catalyst SD-WAN Release 17.x versions. Due to latency differences between tunnels, there may be a transient period where duplicate packets are forwarded to the application.
Packet duplication cannot work in conjunction with local or remote TLOC in the policy. Data policy or AAR is not configured when specifying the packet duplicated tunnel.
Packet duplication is supported only on Cisco IOS XE Catalyst SD-WAN devices but not on all the edge devices.
At the hub, packet duplication cannot be performed for traffic received from spoke1 and forwarded to spoke2 and also vice versa. Packet duplication is not supported for traffic arriving from the WAN (from-tunnel direction) within policy. It is only supported for service-side traffic (from-service direction).

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