[ovs-dev] Odd gre_sys MTU setting (2.6.x vs 2.8.x)

[James Page]

Hi Ben s

On Sat, 13 Jan 2018 at 14:55 James Page <james.page at ubuntu.com> wrote:

> OK, I sent a patch:
>>         https://patchwork.ozlabs.org/patch/860192/
>
>
> Thanks Ben - I'll pull this patch into the Ubuntu packages and test this
> weekend.
>

 I pulled your patch in ontop of our current 2.8.1 packages and re-tested;
I'm not seeing a difference in behaviour with the patch in place. I removed
the vport_gre and ip_gre kernel modules to force a re-creation of the
device on restart of OVS as well as trying a reboot of the test machine:

7: gre0 at NONE: <NOARP> mtu 1476 qdisc noop state DOWN mode DEFAULT group
default qlen 1
    link/gre 0.0.0.0 brd 0.0.0.0
8: gretap0 at NONE: <BROADCAST,MULTICAST> mtu 1462 qdisc noop state DOWN mode
DEFAULT group default qlen 1000
    link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
9: gre_sys at NONE: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1472 qdisc
pfifo_fast master ovs-system state UNKNOWN mode DEFAULT group default qlen
1000
    link/ether 52:ad:6d:89:bb:54 brd ff:ff:ff:ff:ff:ff