From 1a9ae924fd8479485b8e6289a3b015c228967097 Mon Sep 17 00:00:00 2001 From: Rodolfo Alonso Hernandez Date: Fri, 18 Nov 2022 17:40:41 +0100 Subject: [PATCH] Add VXLAN support reference in the OVN installation guide That includes the limitation of ML2/OVN for VXLAN networks to a maximum of 4096 networks and the explanation. Closes-Bug: #1998085 Change-Id: I0b0ba353c219a49acd80edecd0997d1f653b0192 --- doc/source/install/ovn/manual_install.rst | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/doc/source/install/ovn/manual_install.rst b/doc/source/install/ovn/manual_install.rst index 84502c74fc3..1891bf874c8 100644 --- a/doc/source/install/ovn/manual_install.rst +++ b/doc/source/install/ovn/manual_install.rst @@ -201,6 +201,23 @@ primary node. See the :doc:`/ovn/faq/index` for more information. The default for ``max_header_size``, ``30``, is too low for OVN. OVN requires at least ``38``. + * Optionally, enable support for VXLAN type networks. Because of limited + space in VXLAN VNI to pass over the needed information that requires + OVN to identify a packet, the header size to contain the segmentation ID + is reduced to 12 bits, that allows a maximum number of 4096 networks. + The same limitation applies to the number of ports in each network, that + are also identified with a 12 bits header chunk, limiting their number + to 4096 ports. Please check [1]_ for more information. + + .. code-block:: ini + + [ml2] + ... + type_drivers = geneve,vxlan + + [ml2_type_vxlan] + vni_ranges = 1001:1100 + * Optionally, enable support for VLAN provider and self-service networks on one or more physical networks. If you specify only the physical network, only administrative (privileged) users can @@ -354,3 +371,8 @@ Verify operation # ovn-sbctl show + +References +---------- + +.. [1] https://mail.openvswitch.org/pipermail/ovs-dev/2020-September/375189.html