[Rdo-list] R: R: Jumbo MTU to instances in Kilo?

Dan Sneddon dsneddon at redhat.com
Fri Oct 9 17:39:20 UTC 2015


Amedeo,

Thanks for pointing this out. Although the KB article now includes this
setting, some of our other documentation doesn't include this setting.
I'll make sure it gets added.

I'm curious whether anyone has tested out the new MTU-related options
that were added to Kilo:

advertise_mtu
path_mtu
segment_mtu
physnet_mtus

I haven't gotten a chance to test and document these new options
myself. They serve to simplify configuration a bit, but also the new
physnet_mtus option allows you to set a different MTU per interface:

Example:
    physnet_mtus = physnet1:1550, physnet2:1500
Or, to set MTU for physnet2 and leave physnet1 as default:
    physnet_mtus = physnet2:1550

Lastly, has anyone ever run into problems when running (MTU - 50 bytes)
as the veth_mtu with VXLAN? I see documentation all over recommending
(MTU - 100 bytes), but I don't see why VXLAN should take that many
extra bytes. I've done extensive testing at VM MTU 8950 over a 9000 MTU
link, and never run into an issue. Is this just cargo-culting, or is
there a reason to give VXLAN additional headroom in some scenarios?

--
Dan Sneddon         |  Principal OpenStack Engineer
dsneddon at redhat.com |  redhat.com/openstack
650.254.4025        |  dsneddon:irc   @dxs:twitter

On 10/09/2015 05:24 AM, Salvati Amedeo wrote:
> Erich you are welcome in the club :D 
> 
> One side note: as we have rhosp and not rdo, we asked to rh to document this and they wrote a solution on their kb:
> 
> https://access.redhat.com/solutions/1417133
> 
> Regards,
> Amedeo
> 
> -----Messaggio originale-----
> Da: Erich Weiler [mailto:weiler at soe.ucsc.edu] 
> Inviato: giovedì 8 ottobre 2015 18:23
> A: Salvati Amedeo; Pedro Navarro Perez
> Cc: rdo-list at redhat.com
> Oggetto: Re: R: [Rdo-list] Jumbo MTU to instances in Kilo?
> 
> Thanks Amedeo,
> 
> The bit about the config item in the l3_agent.ini file is new to me - I couldn't find that in the documentation, or even as a comment in the file as a config option.  If it is a config item as you point out, maybe it should have a commented section in l3_agent.ini?
> 
> Thanks for the insight!
> 
> cheers,
> erich
> 
> On 10/08/2015 03:02 AM, Salvati Amedeo wrote:
>> Eric,
>>
>> also, to set jumbo frames on your env, you have to set mtu from VM to controller:
>>
>>   # echo "dhcp-option-force=26,8900" > /etc/neutron/dnsmasq-neutron.conf
>>   # openstack-config --set /etc/neutron/dhcp_agent.ini DEFAULT dnsmasq_config_file /etc/neutron/dnsmasq-neutron.conf
>>   # openstack-config --set /etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini agent veth_mtu 8900
>>   # openstack-config --set /etc/neutron/l3_agent.ini DEFAULT network_device_mtu 9000
>>   # openstack-config --set /etc/nova/nova.conf DEFAULT network_device_mtu 9000            <--- this on every nova-compute
>>
>> take a look at l3_agent.ini file, without network_device_mtu every new 
>> router will use default mtu at 1500
>>
>> # ip netns exec qrouter-26f64a08-52ab-4643-b903-9aea6eae047a /bin/bash 
>> # ip a | grep mtu
>> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
>> 69: ha-89546945-ab: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc 
>> noqueue state UNKNOWN
>> 74: qr-f207f652-da: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc 
>> noqueue state UNKNOWN
>> 81: qg-ab978cd0-ad: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc 
>> noqueue state UNKNOWN
>>
>> HTH
>> Amedeo
>>
>> -----Messaggio originale-----
>> Da: rdo-list-bounces at redhat.com [mailto:rdo-list-bounces at redhat.com] 
>> Per conto di Erich Weiler
>> Inviato: giovedì 8 ottobre 2015 01:53
>> A: Pedro Navarro Perez
>> Cc: rdo-list at redhat.com
>> Oggetto: Re: [Rdo-list] Jumbo MTU to instances in Kilo?
>>
>> Actually I was wrong, it WAS on the network node.  The virtual router interfaces were not set to MTU=9000.  On network node:
>>
>> [root at os-net-01 ~]# ip netns
>> qdhcp-c395cff9-af7b-4456-91e3-3c55e6c2c5f5
>> qrouter-0b52e3a6-135c-4481-b286-7c96229f6555
>>
>> i[root at os-net-01 ~]# ip netns exec
>> qrouter-0b52e3a6-135c-4481-b286-7c96229f6555 ifconfig
>> lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
>>           inet 127.0.0.1  netmask 255.0.0.0
>>           inet6 ::1  prefixlen 128  scopeid 0x10<host>
>>           loop  txqueuelen 0  (Local Loopback)
>>           RX packets 0  bytes 0 (0.0 B)
>>           RX errors 0  dropped 0  overruns 0  frame 0
>>           TX packets 0  bytes 0 (0.0 B)
>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>
>> qg-fa1e2a28-25: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>           inet 10.50.100.1  netmask 255.255.0.0  broadcast 10.50.255.255
>>           inet6 fe80::f816:3eff:fe6a:608b  prefixlen 64  scopeid 0x20<link>
>>           ether fa:16:3e:6a:60:8b  txqueuelen 0  (Ethernet)
>>           RX packets 34071065  bytes 5046408745 (4.6 GiB)
>>           RX errors 0  dropped 0  overruns 0  frame 0
>>           TX packets 442  bytes 51915 (50.6 KiB)
>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>
>> qr-51904c89-b8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>           inet 10.100.0.1  netmask 255.255.0.0  broadcast 10.100.255.255
>>           inet6 fe80::f816:3eff:fe37:eca6  prefixlen 64  scopeid 0x20<link>
>>           ether fa:16:3e:37:ec:a6  txqueuelen 0  (Ethernet)
>>           RX packets 702  bytes 75369 (73.6 KiB)
>>           RX errors 0  dropped 0  overruns 0  frame 0
>>           TX packets 814  bytes 92259 (90.0 KiB)
>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>
>> I can fix it manually:
>>
>> [root at os-net-01 neutron]# ip netns exec
>> qrouter-0b52e3a6-135c-4481-b286-7c96229f6555 ifconfig qg-fa1e2a28-25 
>> mtu
>> 9000
>> [root at os-net-01 neutron]# ip netns exec
>> qrouter-0b52e3a6-135c-4481-b286-7c96229f6555 ifconfig qr-51904c89-b8 
>> mtu
>> 9000
>> [root at os-net-01 neutron]# ip netns exec
>> qrouter-0b52e3a6-135c-4481-b286-7c96229f6555 ifconfig
>> lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
>>           inet 127.0.0.1  netmask 255.0.0.0
>>           inet6 ::1  prefixlen 128  scopeid 0x10<host>
>>           loop  txqueuelen 0  (Local Loopback)
>>           RX packets 0  bytes 0 (0.0 B)
>>           RX errors 0  dropped 0  overruns 0  frame 0
>>           TX packets 0  bytes 0 (0.0 B)
>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>
>> qg-fa1e2a28-25: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>           inet 10.50.100.1  netmask 255.255.0.0  broadcast 10.50.255.255
>>           inet6 fe80::f816:3eff:fe6a:608b  prefixlen 64  scopeid 0x20<link>
>>           ether fa:16:3e:6a:60:8b  txqueuelen 0  (Ethernet)
>>           RX packets 34086053  bytes 5048637833 (4.7 GiB)
>>           RX errors 0  dropped 0  overruns 0  frame 0
>>           TX packets 442  bytes 51915 (50.6 KiB)
>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>
>> qr-51904c89-b8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>           inet 10.100.0.1  netmask 255.255.0.0  broadcast 10.100.255.255
>>           inet6 fe80::f816:3eff:fe37:eca6  prefixlen 64  scopeid 0x20<link>
>>           ether fa:16:3e:37:ec:a6  txqueuelen 0  (Ethernet)
>>           RX packets 702  bytes 75369 (73.6 KiB)
>>           RX errors 0  dropped 0  overruns 0  frame 0
>>           TX packets 814  bytes 92259 (90.0 KiB)
>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>
>> And then I have a jumbo clean path everywhere!  All is good then.
>> But...  How to set this in a config file or something so I don't have to do it manually?
>>
>> I found this bug report:
>>
>> https://bugs.launchpad.net/neutron/+bug/1311097
>>
>> Anyone know if that bug is still out there?  Or how can I set virtual router interfaces MTU by default when I create the router?
>>
>> cheers,
>> erich
>>
>> On 10/07/2015 04:35 PM, Erich Weiler wrote:
>>> Actually I think I'm closer - on the compute nodes, I set this in
>>> nova.conf:
>>>
>>> network_device_mtu=9000
>>>
>>> even though there was a big note above it that said not to use it 
>>> because this option was deprecated.  But after setting that option, 
>>> and restarting nova and openvswitch, br-int, my tap device and my qvb 
>>> device all got set to MTU=9000.  So I'm closer!  But still one item 
>>> is blocking me.  I show this tracepath from my controller node direct 
>>> to the VM (which is on a compute node on the local network):
>>>
>>> # tracepath 10.50.100.4
>>>    1?: [LOCALHOST]                                         pmtu 9000
>>>    1:  10.50.100.4                                           0.682ms
>>>    1:  10.50.100.4                                           0.241ms
>>>    2:  10.50.100.4                                           0.297ms pmtu
>>> 1500
>>>    2:  10.50.100.4                                           1.664ms reached
>>>
>>> 10.50.100.4 is the VM.  It looks like the path is jumbo clean up 
>>> until that third hop.  But the thing is, I don't know what the third hop is.
>>> ;)
>>>
>>> On my compute node I still see some stuff with MTU=1500, but I'm not 
>>> sure if one of those is blocking me:
>>>
>>> # ifconfig
>>> br-enp3s0f0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>           inet6 fe80::ec4:7aff:fe58:423e  prefixlen 64  scopeid 0x20<link>
>>>           ether 0c:c4:7a:58:42:3e  txqueuelen 0  (Ethernet)
>>>           RX packets 2401498  bytes 359284253 (342.6 MiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 30  bytes 1572 (1.5 KiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> br-int: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>           inet6 fe80::64dc:94ff:fe35:db4c  prefixlen 64  scopeid 0x20<link>
>>>           ether 66:dc:94:35:db:4c  txqueuelen 0  (Ethernet)
>>>           RX packets 133  bytes 12934 (12.6 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 8  bytes 648 (648.0 B)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> enp3s0f0: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>  mtu 9000
>>>           inet6 fe80::ec4:7aff:fe58:423e  prefixlen 64  scopeid 0x20<link>
>>>           ether 0c:c4:7a:58:42:3e  txqueuelen 1000  (Ethernet)
>>>           RX packets 165957142  bytes 20333410092 (18.9 GiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 23299881  bytes 5950708819 (5.5 GiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> enp3s0f0.50: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>           inet 10.50.1.236  netmask 255.255.0.0  broadcast 10.50.255.255
>>>           inet6 fe80::ec4:7aff:fe58:423e  prefixlen 64  scopeid 0x20<link>
>>>           ether 0c:c4:7a:58:42:3e  txqueuelen 0  (Ethernet)
>>>           RX packets 6014767  bytes 813880745 (776.1 MiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 79301  bytes 19052451 (18.1 MiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
>>>           inet 127.0.0.1  netmask 255.0.0.0
>>>           inet6 ::1  prefixlen 128  scopeid 0x10<host>
>>>           loop  txqueuelen 0  (Local Loopback)
>>>           RX packets 22462729  bytes 1202484822 (1.1 GiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 22462729  bytes 1202484822 (1.1 GiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> qbr922bd9f5-bb: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>           inet6 fe80::4c1a:55ff:feba:14c3  prefixlen 64  scopeid 0x20<link>
>>>           ether 56:a6:a6:db:83:c4  txqueuelen 0  (Ethernet)
>>>           RX packets 16  bytes 1520 (1.4 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 8  bytes 648 (648.0 B)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> qbrf42ea01f-fe: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>>           inet6 fe80::f484:f1ff:fe53:fb2e  prefixlen 64  scopeid 0x20<link>
>>>           ether c2:a6:d8:25:63:ea  txqueuelen 0  (Ethernet)
>>>           RX packets 15  bytes 1456 (1.4 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 8  bytes 648 (648.0 B)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> qvb922bd9f5-bb: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>
>>> mtu
>>> 9000
>>>           inet6 fe80::54a6:a6ff:fedb:83c4  prefixlen 64  scopeid 0x20<link>
>>>           ether 56:a6:a6:db:83:c4  txqueuelen 1000  (Ethernet)
>>>           RX packets 86  bytes 9610 (9.3 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 133  bytes 12767 (12.4 KiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> qvbf42ea01f-fe: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>
>>> mtu
>>> 1500
>>>           inet6 fe80::c0a6:d8ff:fe25:63ea  prefixlen 64  scopeid 0x20<link>
>>>           ether c2:a6:d8:25:63:ea  txqueuelen 1000  (Ethernet)
>>>           RX packets 377  bytes 57664 (56.3 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 333  bytes 38765 (37.8 KiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> qvo922bd9f5-bb: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>
>>> mtu
>>> 9000
>>>           inet6 fe80::b44a:bff:fe72:aaea  prefixlen 64  scopeid 0x20<link>
>>>           ether b6:4a:0b:72:aa:ea  txqueuelen 1000  (Ethernet)
>>>           RX packets 133  bytes 12767 (12.4 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 86  bytes 9610 (9.3 KiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> qvof42ea01f-fe: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>
>>> mtu
>>> 1500
>>>           inet6 fe80::f03e:35ff:fefe:e52  prefixlen 64  scopeid 0x20<link>
>>>           ether f2:3e:35:fe:0e:52  txqueuelen 1000  (Ethernet)
>>>           RX packets 333  bytes 38765 (37.8 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 377  bytes 57664 (56.3 KiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> tap922bd9f5-bb: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>           inet6 fe80::fc16:3eff:fefa:9945  prefixlen 64  scopeid 0x20<link>
>>>           ether fe:16:3e:fa:99:45  txqueuelen 500  (Ethernet)
>>>           RX packets 118  bytes 11561 (11.2 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 95  bytes 10316 (10.0 KiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> virbr0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
>>>           inet 192.168.122.1  netmask 255.255.255.0  broadcast
>>> 192.168.122.255
>>>           ether 52:54:00:c4:75:9f  txqueuelen 0  (Ethernet)
>>>           RX packets 0  bytes 0 (0.0 B)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 0  bytes 0 (0.0 B)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> My network node has all interfaces set to MTU=9000.  I thought maybe the
>>> bottleneck might be there but I don't think it is.   Here's ifconfig
>>> from my network node:
>>>
>>> # ifconfig
>>> lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
>>>           inet 127.0.0.1  netmask 255.0.0.0
>>>           inet6 ::1  prefixlen 128  scopeid 0x10<host>
>>>           loop  txqueuelen 0  (Local Loopback)
>>>           RX packets 2042  bytes 238727 (233.1 KiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 2042  bytes 238727 (233.1 KiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> p1p2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>           inet6 fe80::207:43ff:fe10:deb8  prefixlen 64  scopeid 0x20<link>
>>>           ether 00:07:43:10:de:b8  txqueuelen 1000  (Ethernet)
>>>           RX packets 2156053308  bytes 325330839639 (302.9 GiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 223004  bytes 24769304 (23.6 MiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>           device interrupt 72
>>>
>>> p2p1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>           inet 10.50.1.51  netmask 255.255.0.0  broadcast 10.50.255.255
>>>           inet6 fe80::260:ddff:fe44:2aea  prefixlen 64  scopeid 0x20<link>
>>>           ether 00:60:dd:44:2a:ea  txqueuelen 1000  (Ethernet)
>>>           RX packets 49352916  bytes 3501547231 (3.2 GiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 18876911  bytes 3768900461 (3.5 GiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> p2p2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>           inet6 fe80::260:ddff:fe44:2aeb  prefixlen 64  scopeid 0x20<link>
>>>           ether 00:60:dd:44:2a:eb  txqueuelen 1000  (Ethernet)
>>>           RX packets 2491224974  bytes 348058319500 (324.1 GiB)
>>>           RX errors 0  dropped 0  overruns 0  frame 0
>>>           TX packets 1597  bytes 204525 (199.7 KiB)
>>>           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>> Any way I can figure out what the third hop is from my tracepath?
>>>
>>> Thanks as always for the sage advice!
>>>
>>> -erich
>>>
>>> On 10/07/2015 09:57 AM, Erich Weiler wrote:
>>>> Yeah, I made the changes and then recreated all the networks.  For 
>>>> some reason br-int and the individual virtual instance interfaces on 
>>>> the compute node still show 1500 byte frames.
>>>>
>>>> Has anyone else configured jumbo frames in a Kilo environment?  Or 
>>>> maybe I'm just an outlier...  ;)
>>>>
>>>> -erich
>>>>
>>>> On 10/07/2015 01:46 AM, Pedro Navarro Perez wrote:
>>>>> Hi Erich,
>>>>>
>>>>> did you recreate the neutron networks after the configuration changes?
>>>>>
>>>>> Pedro Navarro Pérez
>>>>> OpenStack product specialist
>>>>> Red Hat Iberia
>>>>> Passeig de Gràcia 120,
>>>>> 08008 Barcelona
>>>>> Spain
>>>>> M +34 639 642 379
>>>>> E pnavarro at redhat.com
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "Erich Weiler" <weiler at soe.ucsc.edu>
>>>>> To: rdo-list at redhat.com
>>>>> Sent: Wednesday, 7 October, 2015 2:34:28 AM
>>>>> Subject: [Rdo-list] Jumbo MTU to instances in Kilo?
>>>>>
>>>>> Hi Y'all,
>>>>>
>>>>> I know someone must have figured this one out, but I can't seem to 
>>>>> get
>>>>> 9000 byte MTUs working.  I have it set in plugin.ini, etc, my nodes 
>>>>> have
>>>>> MTU=9000 on their interfaces, so does the network node.  dnsmasq 
>>>>> also is configured to set MTU=9000 on instances, which works.  But 
>>>>> I still can't ping with large packets to my instance:
>>>>>
>>>>> [weiler at stacker ~]$ ping 10.50.100.2 PING 10.50.100.2 (10.50.100.2)
>>>>> 56(84) bytes of data.
>>>>> 64 bytes from 10.50.100.2: icmp_seq=1 ttl=63 time=2.95 ms
>>>>> 64 bytes from 10.50.100.2: icmp_seq=2 ttl=63 time=1.14 ms
>>>>> 64 bytes from 10.50.100.2: icmp_seq=3 ttl=63 time=0.661 ms
>>>>>
>>>>> That works fine.  This however doesn't work:
>>>>>
>>>>> [root at stacker ~]# ping -M do -s 8000 10.50.100.2 PING 10.50.100.2
>>>>> (10.50.100.2) 8000(8028) bytes of data.
>>>>>    From 10.50.100.2 icmp_seq=1 Frag needed and DF set (mtu = 1500)
>>>>> ping: local error: Message too long, mtu=1500
>>>>> ping: local error: Message too long, mtu=1500
>>>>> ping: local error: Message too long, mtu=1500
>>>>> ping: local error: Message too long, mtu=1500
>>>>>
>>>>> It looks like somehow the br-int interface for OVS isn't set at 
>>>>> 9000, but I can't figure out how to do that...
>>>>>
>>>>> Here's ifconfig on my compute node:
>>>>>
>>>>> br-enp3s0f0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>>>            inet6 fe80::ec4:7aff:fe58:423e  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether 0c:c4:7a:58:42:3e  txqueuelen 0  (Ethernet)
>>>>>            RX packets 2401432  bytes 359276713 (342.6 MiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 30  bytes 1572 (1.5 KiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> br-int: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>>>>            inet6 fe80::64dc:94ff:fe35:db4c  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether 66:dc:94:35:db:4c  txqueuelen 0  (Ethernet)
>>>>>            RX packets 69  bytes 6866 (6.7 KiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 8  bytes 648 (648.0 B)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> enp3s0f0: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>  mtu 9000
>>>>>            inet6 fe80::ec4:7aff:fe58:423e  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether 0c:c4:7a:58:42:3e  txqueuelen 1000  (Ethernet)
>>>>>            RX packets 130174458  bytes 15334807929 (14.2 GiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 22919305  bytes 5859090420 (5.4 GiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> enp3s0f0.50: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
>>>>>            inet 10.50.1.236  netmask 255.255.0.0  broadcast 10.50.255.255
>>>>>            inet6 fe80::ec4:7aff:fe58:423e  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether 0c:c4:7a:58:42:3e  txqueuelen 0  (Ethernet)
>>>>>            RX packets 38429352  bytes 5152853436 (4.7 GiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 419842  bytes 101161981 (96.4 MiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
>>>>>            inet 127.0.0.1  netmask 255.0.0.0
>>>>>            inet6 ::1  prefixlen 128  scopeid 0x10<host>
>>>>>            loop  txqueuelen 0  (Local Loopback)
>>>>>            RX packets 22141566  bytes 1185622090 (1.1 GiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 22141566  bytes 1185622090 (1.1 GiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> qbr247da3ed-a4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>>>>            inet6 fe80::5c8f:c0ff:fe79:bc11  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether b6:1f:54:3f:3d:48  txqueuelen 0  (Ethernet)
>>>>>            RX packets 16  bytes 1472 (1.4 KiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 8  bytes 648 (648.0 B)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> qbrf42ea01f-fe: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>>>>            inet6 fe80::f484:f1ff:fe53:fb2e  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether c2:a6:d8:25:63:ea  txqueuelen 0  (Ethernet)
>>>>>            RX packets 15  bytes 1456 (1.4 KiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 8  bytes 648 (648.0 B)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> qvb247da3ed-a4: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>
>>>>> mtu 1500
>>>>>            inet6 fe80::b41f:54ff:fe3f:3d48  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether b6:1f:54:3f:3d:48  txqueuelen 1000  (Ethernet)
>>>>>            RX packets 247  bytes 28323 (27.6 KiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 233  bytes 25355 (24.7 KiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> qvbf42ea01f-fe: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>
>>>>> mtu 1500
>>>>>            inet6 fe80::c0a6:d8ff:fe25:63ea  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether c2:a6:d8:25:63:ea  txqueuelen 1000  (Ethernet)
>>>>>            RX packets 377  bytes 57664 (56.3 KiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 333  bytes 38765 (37.8 KiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> qvo247da3ed-a4: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>
>>>>> mtu 1500
>>>>>            inet6 fe80::dcfa:f1ff:fe03:ee88  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether de:fa:f1:03:ee:88  txqueuelen 1000  (Ethernet)
>>>>>            RX packets 233  bytes 25355 (24.7 KiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 247  bytes 28323 (27.6 KiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> qvof42ea01f-fe: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>
>>>>> mtu 1500
>>>>>            inet6 fe80::f03e:35ff:fefe:e52  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether f2:3e:35:fe:0e:52  txqueuelen 1000  (Ethernet)
>>>>>            RX packets 333  bytes 38765 (37.8 KiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 377  bytes 57664 (56.3 KiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> tap247da3ed-a4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>>>>            inet6 fe80::fc16:3eff:fede:5eea  prefixlen 64  scopeid 
>>>>> 0x20<link>
>>>>>            ether fe:16:3e:de:5e:ea  txqueuelen 500  (Ethernet)
>>>>>            RX packets 219  bytes 24239 (23.6 KiB)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 224  bytes 26661 (26.0 KiB)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> virbr0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
>>>>>            inet 192.168.122.1  netmask 255.255.255.0  broadcast
>>>>> 192.168.122.255
>>>>>            ether 52:54:00:c4:75:9f  txqueuelen 0  (Ethernet)
>>>>>            RX packets 0  bytes 0 (0.0 B)
>>>>>            RX errors 0  dropped 0  overruns 0  frame 0
>>>>>            TX packets 0  bytes 0 (0.0 B)
>>>>>            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 
>>>>> 0
>>>>>
>>>>> This is on RHEL 7.1.  Any obvious way I can get all the 
>>>>> intermediate bridges to MTU=9000?  I've RTFM'd and googled to no avail...
>>>>>
>>>>> Here's the ovs-vsctl outout:
>>>>>
>>>>> [root at node-136 ~]# ovs-vsctl show
>>>>> 6f5a5f00-59e2-4420-aeaf-7ad464ead232
>>>>>        Bridge br-int
>>>>>            fail_mode: secure
>>>>>            Port br-int
>>>>>                Interface br-int
>>>>>                    type: internal
>>>>>            Port "qvo247da3ed-a4"
>>>>>                tag: 1
>>>>>                Interface "qvo247da3ed-a4"
>>>>>            Port "int-br-eth1"
>>>>>                Interface "int-br-eth1"
>>>>>            Port "int-br-enp3s0f0"
>>>>>                Interface "int-br-enp3s0f0"
>>>>>                    type: patch
>>>>>                    options: {peer="phy-br-enp3s0f0"}
>>>>>        Bridge "br-enp3s0f0"
>>>>>            Port "enp3s0f0"
>>>>>                Interface "enp3s0f0"
>>>>>            Port "br-enp3s0f0"
>>>>>                Interface "br-enp3s0f0"
>>>>>                    type: internal
>>>>>            Port "phy-br-enp3s0f0"
>>>>>                Interface "phy-br-enp3s0f0"
>>>>>                    type: patch
>>>>>                    options: {peer="int-br-enp3s0f0"}
>>>>>        ovs_version: "2.3.1"
>>>>>
>>>>> Many thanks if anyone has any information on this topic!  Or can 
>>>>> point me to some documentation I missed...
>>>>>
>>>>> Thanks,
>>>>> erich
>>>>>
>>>>> _______________________________________________
>>>>> Rdo-list mailing list
>>>>> Rdo-list at redhat.com
>>>>> https://www.redhat.com/mailman/listinfo/rdo-list
>>>>>
>>>>> To unsubscribe: rdo-list-unsubscribe at redhat.com
>>>>>
>>
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