On Mon, Jul 25, 2011 at 3:08 PM, Rangababu Chakravarthula < rb...@hexagrid.com> wrote:
> Thank you Dan. Response below. > > On Mon, Jul 25, 2011 at 11:36 AM, Dan Wendlandt <d...@nicira.com> wrote: > >> Hi Rangababu, >> >> On Sat, Jul 23, 2011 at 12:58 PM, Rangababu Chakravarthula < >> rb...@hexagrid.com> wrote: >> >>> Couple of questions >>> a) How can we address the max 4096 vlan's problem if each user want's a >>> VLAN tagged network? >>> >> >> Currently, the notion of a VLAN is pretty central to the nova networking >> code. >> >> Removing this restriction and enabling more scalable network isolation >> mechanisms is one of the motivations for the Quantum virtual network service >> (see: http://wiki.openstack.org/Quantum). >> >> > >> >>> b) Docs says for each VLAN network, a dhcp server is started. How does it >>> work when we do livemigrate? >>> >> >> Before and after the live migrate, the VM interface should be plugged into >> the same ethernet broadcast domain, so everything will continue to work >> (i.e., addresses from old DHCP lease remains valid, future DHCP requests >> will go to the same DHCP server). >> >> >>>>That answers my question. However if the host on which dnsmasq is > running needs to go down for maintenance, it should hand over the dhcp > responsibility to another compute node. Am I right? > Vish actually did a great write-up on this recently: http://unchainyourbrain.com/openstack/13-networking-in-nova > > >> Dan >> >> >> >> >>> >>> thanks >>> >>> >>> On Wed, Jul 20, 2011 at 11:56 PM, Thor Wolpert <t...@wolpert.ca> wrote: >>> >>>> That was a great explanation, thanks! >>>> >>>> There is also a limit of 12 bits in the 802.1Q protocol, effectively >>>> setting the max to 4096 vlans >>>> >>>> I so look forward to having that kind of problem :)! >>>> >>>> >>>> On Wed, Jul 20, 2011 at 9:26 PM, Jeff Kramer <jeffkra...@gmail.com>wrote: >>>> >>>>> As I understand it, you can setup the tags in the switch first if you >>>>> want, but you don't need to. You will create VLAN tags in the Nova >>>>> database as you create networks with 'nova-manage network create ...', >>>>> and those will be assigned to users on a first-come first-serve basis. >>>>> When a user creates their first node nova assigns them an unused >>>>> network which has a unique VLAN tag. This tag is passed to >>>>> nova-compute when your instance is started, and it feeds that VLAN tag >>>>> into KVM which uses it for all network traffic in a way that's >>>>> transparent to the guest OS. When the guest talks to the network it >>>>> uses that VLAN tag, which the nova-network node is also listening on. >>>>> >>>>> As long as your switch supports host-tagged VLANs (802.1Q), you don't >>>>> have to create the tags in the switch before you use them. You could >>>>> setup all your VLANs before, someone else may have more experience >>>>> with that. >>>>> >>>>> One wrinkle is that many switches have a set number of tagged VLANs >>>>> they can support, for instance the HP V1810-24G switch that I'm using >>>>> supports 64 tagged VLANs, which means my Nova cluster can only have 64 >>>>> different networks (or 64 different users). The next model up >>>>> supports 256, etc. I assume that if you go over this number your >>>>> network traffic will start dropping and weird things will happen. >>>>> >>>>> Your switch's management IPs should probably be in an address space >>>>> that doesn't conflict with what you're assigning with nova. If you're >>>>> using 10.x.x.x for Nova you could put the switch on 192.168.x.x. You >>>>> probably shouldn't be touching the switch from a Nova guest, since the >>>>> time you'll want to be fiddling with it will be when your Nova cluster >>>>> is crashing or otherwise broken. >>>>> >>>>> >>>>> On Wed, Jul 20, 2011 at 10:43 PM, tianyi wang <wangc...@gmail.com> >>>>> wrote: >>>>> > Hi, all >>>>> > >>>>> > >>>>> > If use VLAN mode, it's need setting VLAN in switch's NOS first? >>>>> > And then the setting VLAN in nova controller node? >>>>> > >>>>> > Now, the switch's IP is 192.168.0.234 and the gateway ip address is >>>>> > 192.168.0.1 ( in switch web management interface), should I change >>>>> the >>>>> > switch IP and gateway to 10.0.0.x ? >>>>> > >>>>> > In VLAN mode, what's the relationship tween the controller node's >>>>> VLAN >>>>> > management and switch's NOS VLAN management? >>>>> > >>>>> > thanks >>>>> > >>>>> > >>>>> > alex >>>>> > >>>>> > _______________________________________________ >>>>> > Mailing list: https://launchpad.net/~openstack >>>>> > Post to : openstack@lists.launchpad.net >>>>> > Unsubscribe : https://launchpad.net/~openstack >>>>> > More help : https://help.launchpad.net/ListHelp >>>>> > >>>>> >>>>> >>>>> >>>>> -- >>>>> Jeff Kramer >>>>> jeffkra...@gmail.com >>>>> http://www.jeffkramer.org/ >>>>> >>>>> _______________________________________________ >>>>> Mailing list: https://launchpad.net/~openstack >>>>> Post to : openstack@lists.launchpad.net >>>>> Unsubscribe : https://launchpad.net/~openstack >>>>> More help : https://help.launchpad.net/ListHelp >>>>> >>>> >>>> >>>> _______________________________________________ >>>> Mailing list: https://launchpad.net/~openstack >>>> Post to : openstack@lists.launchpad.net >>>> Unsubscribe : https://launchpad.net/~openstack >>>> More help : https://help.launchpad.net/ListHelp >>>> >>>> >>> >>> _______________________________________________ >>> Mailing list: https://launchpad.net/~openstack >>> Post to : openstack@lists.launchpad.net >>> Unsubscribe : https://launchpad.net/~openstack >>> More help : https://help.launchpad.net/ListHelp >>> >>> >> >> >> -- >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> Dan Wendlandt >> Nicira Networks, Inc. >> www.nicira.com | www.openvswitch.org >> Sr. Product Manager >> cell: 650-906-2650 >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> >> > -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dan Wendlandt Nicira Networks, Inc. www.nicira.com | www.openvswitch.org Sr. Product Manager cell: 650-906-2650 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
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