successfully tested with bug 1743746 ** Tags removed: verification-needed-artful verification-queens-needed ** Tags added: verification-done-artful verification-queens-done
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1742505 Title: gre_sys set to default 1472 when using path_mtu > 1500 with ovs 2.8.x Status in Ubuntu Cloud Archive: Fix Committed Status in Ubuntu Cloud Archive pike series: Fix Committed Status in Ubuntu Cloud Archive queens series: Fix Committed Status in neutron: Invalid Status in linux package in Ubuntu: Confirmed Status in openvswitch package in Ubuntu: Fix Released Status in linux source package in Artful: Confirmed Status in openvswitch source package in Artful: Fix Committed Status in linux source package in Bionic: Confirmed Status in openvswitch source package in Bionic: Fix Released Bug description: [Impact] OpenStack Clouds using GRE overlay tunnels with > 1500 MTU's will observe packet fragmentation/networking issues for traffic in overlay networks. [Test Case] Deploy OpenStack Pike (xenial + pike UCA or artful) Create tenant networks using GRE segmentation Boot instances Instance networking will be broken/slow gre_sys devices will be set to mtu=1472 on hypervisor hosts. [Regression Potential] Minimal; the fix to OVS works around an issue for GRE tunnel port setup via rtnetlink by performing a second request once the gre device is setup to set the MTU to a high value (65000). [Original Bug Report] Setup: Pike neutron 11.0.2-0ubuntu1.1~cloud0 OVS 2.8.0 Jumbo frames setttings per: https://docs.openstack.org/mitaka/networking-guide/config-mtu.html global_physnet_mtu = 9000 path_mtu = 9000 Symptoms: gre_sys MTU is 1472 Instances with MTUs > 1500 fail to communicate across GRE Temporary Workaround: ifconfig gre_sys MTU 9000 Note: When ovs rebuilds tunnels, such as on a restart, gre_sys MTU is set back to default 1472. Note: downgrading from OVS 2.8.0 to 2.6.1 resolves the issue. Previous behavior: With Ocata or Pike and OVS 2.6.x gre_sys MTU defaults to 65490 It remains at 65490 through restarts. This may be related to some combination of the following changes in OVS which seem to imply MTUs must be set in the ovs database for tunnel interfaces and patches: https://github.com/openvswitch/ovs/commit/8c319e8b73032e06c7dd1832b3b31f8a1189dcd1 https://github.com/openvswitch/ovs/commit/3a414a0a4f1901ba015ec80b917b9fb206f3c74f https://github.com/openvswitch/ovs/blob/6355db7f447c8e83efbd4971cca9265f5e0c8531/datapath/vport-internal_dev.c#L186 To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-archive/+bug/1742505/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
