- self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, 1280 + mtu_offset)
- self.assertEqual(1280, self.get_mtu(self.pg1.sw_if_index) - mtu_offset)
+ self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [1280, 0, 0, 0])
+ self.assertEqual(1280, self.get_mtu(self.pg1.sw_if_index))