Open Stack

On 02/10/2015 12:12 AM, mad Engineer wrote:> i dont know whether there 
is any openstack config file to change MTU
 > of integration and tunnel bridge.You can manually update in your os
 > network config file

the ovs switch will have the same mtu as the port with the smallest mtu, 
linux bridge (brctl) will do the same


$ sudo ovs-vsctl add-br hola
$ ifconfig hola
hola      Link encap:Ethernet  HWaddr 3a:e9:3a:a1:03:4a
           BROADCAST MULTICAST  MTU:1500  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

$ sudo modprobe dummy
$ sudo ifconfig dummy0 up
yydesk:~$ ifconfig dummy0
dummy0    Link encap:Ethernet  HWaddr d2:86:e9:e3:b2:62
           inet6 addr: fe80::d086:e9ff:fee3:b262/64 Scope:Link
           UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
           TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:0 (0.0 B)  TX bytes:140 (140.0 B)

$ sudo ifconfig dummy0 mtu 5000
$ sudo ovs-vsctl add-port  hola dummy0
$ ifconfig hola
hola      Link encap:Ethernet  HWaddr 3a:e9:3a:a1:03:4a
           BROADCAST MULTICAST  MTU:5000  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

$ ifconfig dummy0
dummy0    Link encap:Ethernet  HWaddr d2:86:e9:e3:b2:62
           inet6 addr: fe80::d086:e9ff:fee3:b262/64 Scope:Link
           UP BROADCAST RUNNING NOARP  MTU:5000  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
           TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:0 (0.0 B)  TX bytes:210 (210.0 B)




>
> i am using ubuntu servers so added this in /etc/network/interfaces
> added br-tun.br-int and physical NIC with new MTU value
>
> eg:
> auto br-tun
> iface br-tun inet static
> address 0.0.0.0
> MTU 8900
>
>
> auto eth3
> iface eth3 inet static
> address 172.16.10.3
> netmask 255.255.255.0
> mtu 8900
>
> for changing MTU of linux bridge i suppose its "qbr-"  add
> network_device_mtu = 8900 in nova.conf on compute nodes.
>
> On Mon, Feb 9, 2015 at 7:05 PM, Danny Choi (dannchoi)
> <dannchoi at cisco.com> wrote:
>> Hello,
>>
>> Can you tell me exactly how to change the br-tun and br-int in its config
>> file?
>> Which file and where?
>>
>> I’m using OVS which by default also has the Linux bridge.  How to take care
>> of it?
>>
>> Thanks,
>> Danny
>>
>>
>> -------------------------------------------
>> Date: Mon, 9 Feb 2015 15:01:57 +0530
>> From: mad Engineer <themadengin33r at gmail.com>
>> To: Eren T?rkay <erent at skyatlas.com>
>> Cc: "openstack at lists.openstack.org" <openstack at lists.openstack.org>
>> Subject: Re: [Openstack] higher MTU for all interfaces
>> Message-ID:
>> <CAN8oO4A_XcGM86_KxEySKOa_wOf1ZQwwOSMgmhtdKLtjFtF6vw at mail.gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> thanks,i manually changed br-tun br-int in its network config file and
>> now its working across reboot.
>>
>>
>> On Mon, Feb 9, 2015 at 12:42 PM, Eren T?rkay <erent at skyatlas.com> wrote:
>>
>> On 08-02-2015 21:56, mad Engineer wrote:
>>
>> Hello all is there any way we can change MTU of all relevant
>> interfaces of instances,if i set
>> dhcp-option-force=26,1400 will it change MTU of all relevant
>> interfaces like qbr qvo br-int etc etc
>> is there any way to change MTU of all neutron interfaces.
>>
>>
>> Hello,
>>
>> There is an option "network_device_mtu" on nova.conf. When tap,qvo,qbr
>> bridges
>> are setup, it will use this setting to set MTU. However, from my experience,
>> there is no setting to set br-tun, br-int MTU setting.
>>
>> I need to note that DHCP option will only cause MTU setting inside VMs.
>>
>> You can follow the bug report about setting MTUs on br-int, br-tun
>> interfaces.
>>
>> https://bugs.launchpad.net/neutron/+bug/1419069
>>
>> Regards,
>> Eren
>>
>> --
>> System Administrator
>> https://skyatlas.com/
>>
>> _______________________________________________
>> Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
>> Post to     : openstack at lists.openstack.org
>> Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
>>
>>
>>
>
> _______________________________________________
> Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
> Post to     : openstack at lists.openstack.org
> Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
>

-- 
1AE0 322E B8F7 4717 BDEA BF1D 44BB 1BA7 9F6C 6333