Tested OK on Xenial with Pike UCA:
16: gre_sys@NONE: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65000 qdisc pfifo_fast master ovs-system state UNKNOWN mode DEFAULT group default qlen 1000 link/ether 56:5c:6e:19:f5:4b brd ff:ff:ff:ff:ff:ff
However testing on artful currently blocked pending resolution of bug 1743746 which prevents an increase in the MTU of the gre devices.
Tested OK on Xenial with Pike UCA:
16: gre_sys@NONE: <BROADCAST, MULTICAST, UP,LOWER_ UP> mtu 65000 qdisc pfifo_fast master ovs-system state UNKNOWN mode DEFAULT group default qlen 1000
link/ether 56:5c:6e:19:f5:4b brd ff:ff:ff:ff:ff:ff
However testing on artful currently blocked pending resolution of bug 1743746 which prevents an increase in the MTU of the gre devices.