I built a test kernel with commit cfddd4c. The test kernel can be downloaded from: http://kernel.ubuntu.com/~jsalisbury/lp1743746
Can you test this kernel and see if it resolves this bug? Note, to test this kernel, you need to install both the linux-image and linux-image-extra .deb packages. Thanks in advance! -- 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/1743746 Title: 4.13: unable to increase MTU configuration for GRE devices Status in linux package in Ubuntu: In Progress Status in linux source package in Artful: In Progress Bug description: [Impact] GRE overlay networks can't carry traffic with MTU > 1500 [Test Case] sudo add-apt-repository cloud-archive:pike sudo apt update sudo apt install openvswitch-switch sudo ovs-vsctl add-br br-tun sudo ovs-vsctl add-port br-tun gre0 -- set interface gre0 type=gre options:remote_ip=10.100.1.1 gre_sys device will be configured with MTU 1472. sudo ip link set gre_sys mtu 65000 will fail with EINVAL. [Regression Potential] [Bug Report] Under Linux 4.13 its not possible to configure GRE tunnel devices with a MTU larger than 1500; this impacts on Open vSwitch (which creates tunnel devices for GRE overlay networking) and the ip tools. The kernel will error with: gre_sys: Invalid MTU 65000 requested, hw max 1500 The side effect of this is that if overlay networks are configured with high MTUs, the gre devices fragment the packets and networking is generally slow/broken. This is resolved as part of the upcoming 4.15 kernel under: https://github.com/torvalds/linux/commit/cfddd4c33c254954927942599d299b3865743146 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1743746/+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
