Somebody setting network.trr.mode =3 is clearly asking Firefox to be DNS-silent (standard resolution). The fact that instead the user gets a beacon at the beginning and end of the session is rather unexpected.
Bug 1593873 Comment 6 Edit History
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Somebody setting network.trr.mode =3 is clearly asking Firefox to be DNS-silent (standard resolution). The fact that instead the user gets a beacon at the beginning and end of the session is rather unexpected. From the wiki https://wiki.mozilla.org/Trusted_Recursive_Resolver, the native resolver is NEVER used. 3 - Only. Only use TRR. Never use the native (This mode also requires the bootstrapAddress pref to be set)