I have a Debian Jessie 8.2 server serving as an Xen VM host. The server has two physical network interfaces that are bonded together using LACP. There is also an xenbr0 interface. I would like to enable jumbo frames, however I am unable to. Here's the network configuration:auto eth0iface eth0 inet manual   bondmaster bond0   mtu 9000auto eth1iface eth1 inet manual   bondmaster bond0   mtu 9000auto bond0iface bond0 inet manual   bond-mode 4   bond-miimon 100   bond-lacp-rate 1   bond-slaves eth0 eth1   mtu 9000auto xenbr0iface xenbr0 inet static   bridge_ports bond0   address 10.0.0.12   gateway 10.0.0.1   netmask 255.255.255.0   mtu 9000After adding MTU to each interface, I ran sudo ifdown bond0 && sudo ifup bond0. The MTU is still reported as 1,500. I then tried the same with the xenbr0 interface, however I get the following output:user@host:~$ sudo ifdown xenbr0 && sudo ifup xenbr0ifdown: interface xenbr0 not configuredWaiting for xenbr0 to get ready (MAXWAIT is 32 seconds).RTNETLINK answers: File existsFailed to bring up xenbr0.Here's the output from ip a, without virtual interfaces for VM guests:1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00    inet 127.0.0.1/8 scope host lo       valid_lft forever preferred_lft forever    inet6 ::1/128 scope host        valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000    link/ether e8:94:f6:08:aa:30 brd ff:ff:ff:ff:ff:ff3: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000    link/ether e8:94:f6:08:aa:30 brd ff:ff:ff:ff:ff:ff4: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue master xenbr0 state UP group default     link/ether e8:94:f6:08:aa:30 brd ff:ff:ff:ff:ff:ff17: xenbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default     link/ether e8:94:f6:08:aa:30 brd ff:ff:ff:ff:ff:ff    inet 10.0.0.12/24 brd 10.0.0.255 scope global xenbr0       valid_lft forever preferred_lft forever    inet6 2001:****:****:****:****:****:****:****/64 scope global mngtmpaddr dynamic        valid_lft 2591736sec preferred_lft 604536sec    inet6 fe80::ea94:f6ff:fe08:aa30/64 scope link        valid_lft forever preferred_lft foreverWhat have I done wrong?
How can I enable jumbo frames on a bonded Xen bridge interface?
debian;networking