Broadly speaking, UDP applications which rely on IP packet fragmentation are broken as designed.  If you wanted reliable transport you would have used TCP or a higher level abstraction.  If you wanted simple transport of large data chunks, you would have chosen likewise.  You picked UDP because you have latency requirements that cannot be met by TCP, and that means you need to know what your packets are actually doing, and that includes fragmentation.<p>If you want to play in that world you need to be prepared to handle MTU discovery on your own, or else design your app around deliberately small packet sizes.<p>That&#x27;s not to say that this isn&#x27;t a bug.  But let&#x27;s not start editorializing our titles: the apps for which GCE is &quot;unusable&quot; are buggy apps to start with.