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Update vxlan.rst
Added section about MTU sizes and examples.
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andrijapanic committed Nov 26, 2014
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@@ -73,6 +73,16 @@ To check the capability of your system, execute the following commands.
# If it's not, your iproute2 utility doesn't support VXLAN.

Important note on MTU size
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When new vxlan interfaces are created, kernel will obtain current MTU size of the physical interface (ethX or the bridge)
and then create vxlan interface/bridge that are exactly 50 bytes smaller than the MTU on physical interface/bridge.
This means that in order to support default MTU size of 1500 bytes inside VM, your vxlan interface/bridge must also
have MTU of 1500 bytes, meaning that your physical interface/bridge must have MTU of at least 1550 bytes.
In order to configure "jumbo frames" you can i.e. make physical interface/bridge with 9000 bytes MTU, then all the vxlan
interfaces will be created with MTU of 8950 bytes, and then MTU size inside VM can be set to 8950 bytes.

Advanced: Build kernel and iproute2
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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