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<DIV><FONT color=#000000 size=3 face=宋体></FONT> </DIV>
<DIV><FONT color=#000000 size=3 face=宋体></FONT> </DIV>
<DIV align=left><FONT color=#c0c0c0 size=2
face=Verdana>2011-11-22</FONT></DIV><FONT size=2 face=Verdana>
<HR style="WIDTH: 122px; HEIGHT: 2px" align=left SIZE=2>
<DIV><FONT color=#c0c0c0 size=2 face=Verdana><SPAN
id=_FlashSignName>shamaya</SPAN></FONT></DIV></FONT>
<DIV>
<HR>
</DIV>
<DIV>发件人: "shamaya"<shamaya@126.com></DIV>
<DIV>发送时间: 2011-11-22 09:30</DIV>
<DIV>主 题: 回复: Re: [one-users] what a virtual network means?</DIV>
<DIV>收件人: "Hutson Betts"<A
href="mailto:hut101@tamu.edu">hut101@tamu.edu</A></DIV>
<DIV><BR><BR></DIV><STATIONERY>
<DIV>
<DIV><FONT face=宋体> I have a question and two advices for OpenNebula's
network configuration</FONT></DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体>Question:</FONT></DIV>
<DIV><FONT face=宋体>1. Can I use VLAN function on a "physical network" which
already running VLAN on the phical swich? (you know, in Eucalyptus, VLAN cann't
function properly in such a environment: "underlying physical network must be
VLAN clean", <A
href="http://open.eucalyptus.com/wiki/EucalyptusNetworkConfiguration_v2.0">http://open.eucalyptus.com/wiki/EucalyptusNetworkConfiguration_v2.0</A>)</FONT></DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体>Document advices:</FONT></DIV>
<DIV><FONT face=宋体>1. Maybe, User's life would be more easier if OpenNebula's
document on network include a network configuration example to help user
build their cloud on their data center, for both physical and logical network
configuration. again, Eucalyptus have included such guides for users at <A
href="http://open.eucalyptus.com/learn/InstallingECC">http://open.eucalyptus.com/learn/InstallingECC</A></FONT></DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体>2. Mybe it is helpful to give a throughout network
configuration process expample, e.g. you mentioned cloud builder need to setup a
bridge on every work node, but I did found a example. </FONT></DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体>Cheers,</FONT></DIV>
<DIV><FONT face=宋体>Sha</FONT></DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT face=宋体></FONT> </DIV>
<DIV><FONT color=#000000 size=3 face=宋体></FONT> </DIV>
<DIV align=left><FONT color=#c0c0c0 size=2
face=Verdana>2011-11-22</FONT></DIV><FONT size=2 face=Verdana>
<HR style="WIDTH: 122px; HEIGHT: 2px" align=left SIZE=2>
<DIV><FONT color=#c0c0c0 size=2 face=Verdana><SPAN
id=_FlashSignName>shamaya</SPAN></FONT></DIV></FONT>
<DIV>
<HR>
</DIV>
<DIV>发件人: Hutson Betts <hut101@tamu.edu></DIV>
<DIV>发送时间: 2011-11-21 12:14</DIV>
<DIV>主 题: Re: [one-users] what a virtual network means?</DIV>
<DIV>收件人: shamaya <shamaya@126.com></DIV>
<DIV><BR><BR></DIV>
<DIV>Dear Sha, </DIV>
<DIV> </DIV>
<DIV>Have you had an opportunity to read through Managing Virtual Networks </DIV>
<DIV>3.0 (http://opennebula.org/documentation:rel3.0:vgg)? Honestly, I think </DIV>
<DIV>it covers virtual networking better than any of the other OpenNebula </DIV>
<DIV>configuration documents. </DIV>
<DIV> </DIV>
<DIV>However, I would look outside of OpenNebula for a truly in-depth </DIV>
<DIV>analysis of virtual networking, VLANs, and cloud networks. </DIV>
<DIV> </DIV>
<DIV>But, to answer your question, a single virtual network is analogous to a </DIV>
<DIV>physical switch containing a DHCP server. Virtual machines attached to </DIV>
<DIV>this "physical" switch are isolated from network traffic on another </DIV>
<DIV>"physically separated" switch, which in this case is another virtual </DIV>
<DIV>network. </DIV>
<DIV> </DIV>
<DIV>Now, with regard to the DHCP server, OpenNebula allows virtual networks </DIV>
<DIV>to lease IP addresses to virtual machines that attach to the network. </DIV>
<DIV>Each IP address can only be leased, or owned, by one virtual machine on </DIV>
<DIV>that virtual network at any one time. When a virtual machine starts, it </DIV>
<DIV>is automatically assigned an IP address by OpenNebula. The trick is to </DIV>
<DIV>know that the MAC address assigned to the virtual machine is a </DIV>
<DIV>transformation of the IP address. </DIV>
<DIV> </DIV>
<DIV>Consider an example in the document linked earlier: </DIV>
<DIV>A MAC address of: 00:03:c0:a8:00:01 </DIV>
<DIV>Corresponds to an IP address of: 192.168.0.1 </DIV>
<DIV>You can do the hex to int conversion: </DIV>
<DIV>c0 = 192 </DIV>
<DIV>a8 = 168 </DIV>
<DIV> </DIV>
<DIV>Now, from a computer perspective, there are quite a few ways to isolate </DIV>
<DIV>the network traffic between virtual networks, i.e., vlans, ebtables for </DIV>
<DIV>mac filtering, Open eSwitch. etc. This part you must consider carefully </DIV>
<DIV>when you wish to expand beyond one virtual machine host, or when you </DIV>
<DIV>want to use overlapping IP ranges for different virtual networks. </DIV>
<DIV> </DIV>
<DIV>From an administrator point, all that is required of you is to create a </DIV>
<DIV>bridge, and attach it to a physical Ethernet (network) interface on your </DIV>
<DIV>virtual machine host. </DIV>
<DIV> </DIV>
<DIV>Next, when creating new virtual networks using network templates, you </DIV>
<DIV>can specify the name of that bridge. Also, if you decide to use OCCI, </DIV>
<DIV>you can specify in the OCCI configuration file, the name of that bridge </DIV>
<DIV>as well. </DIV>
<DIV> </DIV>
<DIV>As you've already hinted at, when virtual machines are created, their </DIV>
<DIV>virtual network interfaces are attached to the bridge, either directly, </DIV>
<DIV>or by another mechanism such as when using VLAN tagging. In either case, </DIV>
<DIV>the bridge acts as the central "physical" switch for your virtual </DIV>
<DIV>networks, passing traffic between virtual machines. </DIV>
<DIV> </DIV>
<DIV>Now, because the bridge is attached to your virtual machine host's </DIV>
<DIV>physical network interface, your virtual machines will also be able to </DIV>
<DIV>send traffic to virtual machines on other virtual machine hosts on the </DIV>
<DIV>same physical switch, literally the physical switch this time. </DIV>
<DIV> </DIV>
<DIV>Please let me know if my explanations could use refinements, or if you </DIV>
<DIV>have any further questions. Also feel free to write out a list of ideas </DIV>
<DIV>you have for improving the documentation on OpenNebula. I'm sure the </DIV>
<DIV>community would greatly appreciate any help you're able to provide. </DIV>
<DIV> </DIV>
<DIV>-- </DIV>
<DIV>Hutson Betts </DIV>
<DIV>Computer Science and Engineering </DIV>
<DIV>Texas A&M University </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>On Mon, 2011-11-21 at 10:02 +0800, shamaya wrote: </DIV>
<DIV>> Hi all, </DIV>
<DIV>> OpenNebula's document on network seems a bit incomplete, and I feel It's difficult to understand what a virtual network means? Does a vritual network means create a bridge on a host and connect all VMs of that host to it? Can a virutal network span two host and let VMs of the two form a private network? </DIV>
<DIV>> </DIV>
<DIV>> Regards. </DIV>
<DIV>> </DIV>
<DIV>> Sha </DIV>
<DIV>> </DIV>
<DIV>> 2011-11-21 </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> shamaya </DIV>
<DIV>> _______________________________________________ Users mailing list Users@lists.opennebula.org http://lists.opennebula.org/listinfo.cgi/users-opennebula.org </DIV>
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