Feature history for TCP MSS and clear dont fragment

Updated: April 24, 2026

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Details the evolution and key enhancements of the TCP MSS and clear don't fragment features, highlighting major updates and functional milestones released across versions.

Table 1. Feature History
Feature Name	Release Information	Description
Configure TCP MSS	Cisco IOS XE Catalyst SD-WAN Release 17.5.1a Cisco vManage Release 20.5.1	This feature adds support for TCP MSS adjustment on Cisco IOS XE Catalyst SD-WAN devices on both directions of the Cisco Catalyst SD-WAN tunnel interface.
Configure Clear Don’t Fragment Option	Cisco IOS XE Catalyst SD-WAN Release 17.5.1a Cisco vManage Release 20.5.1	This feature provides the option to clear the Don't Fragment bit in the IPv4 packet header for packets being sent out on a Cisco Catalyst SD-WAN tunnel . When you clear the Don't Fragment configuration, packets larger than the interface MTU are fragmented before being sent.

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