Hi! I am trying to set the MTU to 9000. ip link set dev br0 mtu 9000 It does work after running the command. ip link show br0 4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether 22:6c:63:46:7e:67 brd ff:ff:ff:ff:ff:ff But adding it to my configuration like this: auto lo iface lo inet loopback auto eth0 iface eth0 inet manual pre-up ip link set dev eth0 mtu 9000 auto br0 iface br0 inet static address 192.168.1.41 netmask 255.255.255.0 gateway 192.168.1.1 dns-nameservers 192.168.0.113 bridge_ports eth0 bridge_stp off bridge_fd 0 mtu 9000 post-up ip link set dev br0 mtu 9000 The result after a restart is eth0 got MTU 9000 but br0 sticks to 1500. I can change it and seems to work fine. Tested it like that: ping -M do -s 8950 192.168.1.42 Also I noticed runing service networking restart && ip link show br0 Shows the MTu 9000 is set once. I also have an working OVN and OpenVSwitch on that machines. Is it OVN/OVS that makes it comming out like that? Greetings filip