openstack/devstack
Code Issues Proposed changes

neutron: enable ml2 mtu calculation mechanism

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Setting path_mtu to reflect mtu for physical devices that handle traffic
issued from br-tun makes ml2 plugin to calculate mtu for tenant networks
properly, considering encapsulation headers. After that, calculated mtu
values can be propagated into instances (currently, only DHCP approach
is implemented; RA support for IPv6 subnets is under review).

This change allows to run tunnelled tenant networks in multinode when
underlying physical devices don't support jumbo frames.

Note: changing the default value in neutron would not be backwards
compatible, since it could slow down east-west tunnelled traffic in
clouds that run on jumbo-aware networks.

Change-Id: I8287677c7ad0f13fa9f5cb194f9372d04b78cb61
Related-Bug: #1527675
This commit is contained in:
Ihar Hrachyshka 2016-01-14 15:31:31 +01:00
parent ea7fd55153
commit 06cfce3756
1 changed files with 12 additions and 0 deletions
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12
lib/neutron_plugins/ml2
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@ -40,6 +40,12 @@ Q_ML2_PLUGIN_EXT_DRIVERS=${Q_ML2_PLUGIN_EXT_DRIVERS-port_security}
# L3 Plugin to load for ML2
ML2_L3_PLUGIN=${ML2_L3_PLUGIN:-neutron.services.l3_router.l3_router_plugin.L3RouterPlugin}
# Underlying path MTU for physical network managing br-tun; use '-' instead of
# ':-' to allow people to explicitly override this to blank, to disable
# automatic MTU calculation for tunnelled tenant networks
Q_ML2_PLUGIN_PATH_MTU=${Q_ML2_PLUGIN_PATH_MTU-1500}
function populate_ml2_config {
CONF=$1
SECTION=$2
@ -77,6 +83,12 @@ function neutron_plugin_configure_service {
echo "WARNING - The ml2 plugin is using local tenant networks, with no connectivity between hosts."
fi
# Enable ml2 mtu calculation mechanism for networks by providing path mtu
# value for physical devices that are used for br-tun traffic
if [[ "$ENABLE_TENANT_TUNNELS" == "True" ]] && [[ "$Q_ML2_PLUGIN_PATH_MTU" != "" ]]; then
iniset /$Q_PLUGIN_CONF_FILE ml2 path_mtu "$Q_ML2_PLUGIN_PATH_MTU"
fi
# Allow for overrding VLAN configuration (for example, to configure provider
# VLANs) by first checking if Q_ML2_PLUGIN_VLAN_TYPE_OPTIONS is set.
if [ "$Q_ML2_PLUGIN_VLAN_TYPE_OPTIONS" == "" ]; then