Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-28 Thread Cory Benfield
On Tue, Oct 28, 2014 at 08:32:11, Li Tianqing wrote: > One more question. > Vxlan use udp, how can vxlan promise reliability. > It can't, but that doesn't matter. VXLAN emulates a single layer 2 broadcast domain: conceptually, a series of machines all plugged into the same Ethernet switch. This

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-28 Thread A, Keshava
Ian Wells [mailto:ijw.ubu...@cack.org.uk<mailto:ijw.ubu...@cack.org.uk>] Sent: Tuesday, October 28, 2014 11:40 AM To: OpenStack Development Mailing List (not for usage questions) Subject: Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxl

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-28 Thread Li Tianqing
One more question. Vxlan use udp, how can vxlan promise reliability. 在 2014-10-28 15:51:02,"Ian Wells" 写道: On 28 October 2014 00:30, Li Tianqing wrote: lan, you are right, the receiver only receive packet that small than 1450. Because the sender does not send large packets at the begining, s

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-28 Thread Ian Wells
On 28 October 2014 00:30, Li Tianqing wrote: > lan, you are right, the receiver only receive packet that small than 1450. > Because the sender does not send large packets at the begining, so > tcpdump can catch some small packets. > > Another question about the mtu, what if we clear the DF in th

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-28 Thread Ian Wells
; > > … > > Thanks & regards, > > Keshava > > > > *From:* Ian Wells [mailto:ijw.ubu...@cack.org.uk] > *Sent:* Tuesday, October 28, 2014 11:40 AM > *To:* OpenStack Development Mailing List (not for usage questions) > *Subject:* Re: [openstack-dev] [neut

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-28 Thread Li Tianqing
lan, you are right, the receiver only receive packet that small than 1450. Because the sender does not send large packets at the begining, so tcpdump can catch some small packets. Another question about the mtu, what if we clear the DF in the ip packets? Then l2 can split packets into smalle

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-28 Thread A, Keshava
tack Development Mailing List (not for usage questions) Subject: Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan Path MTU discovery works on a path - something with an L3 router in the way - where the outbound interface has a smaller MTU than

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-28 Thread Li Tianqing
The problem is that it is not at the begining to transmit large file. It is after some packets trasmited, then the connection is choked. After the connection choked, from the bridge in compute host we can see the sender send packets, and the receiver can not get the packets. If it is the pmtud,

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-27 Thread Ian Wells
Path MTU discovery works on a path - something with an L3 router in the way - where the outbound interface has a smaller MTU than the inbound one. You're transmitting across an L2 network - no L3 routers present. You send a 1500 byte packet, the network fabric (which is not L3, has no address, and

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-27 Thread Li Tianqing
-- Best Li Tianqing At 2014-10-27 17:42:41, "Ihar Hrachyshka" wrote: >-BEGIN PGP SIGNED MESSAGE- >Hash: SHA512 > >On 27/10/14 02:18, Li Tianqing wrote: >> Hello, Right now, we test neutron under havana release. We >> configured network_device_mtu=1450 in neutron.conf, After c

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-27 Thread Kyle Mestery
On Mon, Oct 27, 2014 at 4:42 AM, Ihar Hrachyshka wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA512 > > On 27/10/14 02:18, Li Tianqing wrote: >> Hello, Right now, we test neutron under havana release. We >> configured network_device_mtu=1450 in neutron.conf, After create >> vm, we found th

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-27 Thread Ihar Hrachyshka
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 On 27/10/14 02:18, Li Tianqing wrote: > Hello, Right now, we test neutron under havana release. We > configured network_device_mtu=1450 in neutron.conf, After create > vm, we found the vm interface's mtu is 1500, the ping, ssh, is ok. > But if we scp

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-26 Thread Li Tianqing
Thanks, it helps a lot. But i want to know, why the mtu discovery can not find the appropriate mtu to send? In http://www.chriscowley.me.uk/blog/2014/03/31/openstack-neutron-performance-problems/, it says that "Everything matches, however I was using GRE tunnels, which add a header to each f

Re: [openstack-dev] [neutron] vm can not transport large file under neutron ml2 + linux bridge + vxlan

2014-10-26 Thread Damon Wang
Hi Tangqing, This is a well-known problem, it is because GRE/VxLan 's packet header use some bytes, length of data packet should reduced. You can get refer to bellow pages: http://www.chriscowley.me.uk/blog/2014/03/31/openstack-neutron-performance-problems/ https://ask.openstack.org/en/question/25