[2/4] cloudstack-docs git commit: Update vxlan.rst

[bh...@apache.org]

Update vxlan.rst

Added section about MTU sizes and examples.

Project: http://git-wip-us.apache.org/repos/asf/cloudstack-docs/repo
Commit: http://git-wip-us.apache.org/repos/asf/cloudstack-docs/commit/cbd7a136
Tree: http://git-wip-us.apache.org/repos/asf/cloudstack-docs/tree/cbd7a136
Diff: http://git-wip-us.apache.org/repos/asf/cloudstack-docs/diff/cbd7a136

Branch: refs/heads/master
Commit: cbd7a13622780142127f06bf2f0d2888afea3c68
Parents: be0f4dd
Author: andrijapanic <an...@users.noreply.github.com>
Authored: Wed Nov 26 13:10:32 2014 +0100
Committer: andrijapanic <an...@users.noreply.github.com>
Committed: Wed Nov 26 13:10:32 2014 +0100

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 rtd/source/networking/vxlan.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)
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http://git-wip-us.apache.org/repos/asf/cloudstack-docs/blob/cbd7a136/rtd/source/networking/vxlan.rst
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diff --git a/rtd/source/networking/vxlan.rst b/rtd/source/networking/vxlan.rst
index d3b54a8..85da616 100644
--- a/rtd/source/networking/vxlan.rst
+++ b/rtd/source/networking/vxlan.rst
@@ -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
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+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
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~