Limits RegistryPUBLIC RECORDLimits RegistryResearch Console →Default TCP MSS for IPv6 is 1220 bytes under RFC 9293 TCP over IPv6 when no MSS option is received. The value is derived as 1280 minus 60 header bytes.
The question, scope, and sources behind this Registry record.
Under RFC 9293 TCP over IPv6 when no MSS option is received, what exact standards-defined value applies to default send MSS?
Current frontiers derived from accepted Claims.
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Assertions tied to evidence, attribution, and review.
The frontier as it changed over time.
Only accepted Claims matching the current specification contribute to the displayed bounds. Strict inequalities remain open; contradictory Claims require editorial review.