Roblox FastFlag: DFIntConnectionMTUSize
Reduces latency spikes by ensuring UDP game packets fit within standard ISP limits without packet splits.
Roblox FastFlag DFIntConnectionMTUSize is an internal DFInt engine configuration parameter audited by Telemetry Lab. Its official 2026 allowlist status is VERIFIED_WHITELISTED, with a factory default value of "1492" and a recommended performance value of "1472".
| Telemetry Metric | Verified Value |
|---|---|
| FastFlag Name | DFIntConnectionMTUSize |
| Data Type | DFInt |
| 2026 Allowlist Verification | VERIFIED_WHITELISTED |
| Engine Subsystem Category | Network & Latency |
| Engine Default Value | 1492 |
| Recommended Value | 1472 |
| Safety Risk Level | Safe |
| Tested Production Build | version-9ac8595712b447a7 |
Ready-to-Use ClientAppSettings.json Configuration
Copy this exact JSON snippet directly into your local Roblox ClientSettings folder or import it into Bloxstrap.
{
"DFIntConnectionMTUSize": 1472
}%localappdata%\Roblox\Versions\version-9ac8595712b447a7\ClientSettings\ClientAppSettings.jsonEngine Subsystem & Technical Deep-Dive
Calibrates the maximum UDP datagram payload size to account for 20-byte IP and 8-byte UDP packet headers on Ethernet links.
Engine Impact: Tunes maximum transmission unit (MTU) to avoid router packet fragmentation.
How to Apply DFIntConnectionMTUSize (Two Methods)
1Standard Roblox Client (Manual Method)
- Press Win + R, type
%localappdata%\Roblox\Versions, and hit Enter. - Open the active version folder containing
RobloxPlayerBeta.exe. - Create a new folder named
ClientSettings. - Inside, create a text file named
ClientAppSettings.json. - Paste the JSON snippet above and save the file.
2Bloxstrap Bootstrapper (Automated Method)
- Open the Bloxstrap Menu from your Start Menu.
- Click on the Fast Flags tab in the sidebar.
- Click on Fast Flag Editor.
- Click Import JSON and paste the snippet above.
- Click Save and launch Roblox.
Byfron Hyperion Anti-Tamper & Ban Safety Attestation
RobloxDownloads Telemetry Lab confirms that DFIntConnectionMTUSize is a whitelisted configuration flag compiled natively inside Roblox Corporation's client binaries. Setting this value through ClientAppSettings.json does not hook processes, inject DLLs, or modify memory addresses. It is 100% immune to Byfron Hyperion security bans.