[CentOS-virt] understanding problems

[lee]

SilverTip257 <silvertip257 at gmail.com> writes:

> On Fri, Jun 13, 2014 at 8:42 AM, lee <lee at yun.yagibdah.de> wrote:
>
>> Peter <peter at pajamian.dhs.org> writes:
>>
>> > On 06/12/2014 05:17 PM, lee wrote:
>> >> I knew before I started that network setup would be a PITA because years
>> >> ago, I set up a VM for someone who didn't have a 64bit system to compile
>> >> a 64bit version of some software.  The network setup being so
>> >> ridiculously difficult has kept me from touching VMs ever again for
>> >> years.  It's just too difficult and not worth the effort unless you're
>> >> really forced to do it.
>> >
>> > Networking can be confusing until it "clicks" then it all seems to fall
>> > into place, there is a certain amount of understanding of the overall
>> > picture of how bridge networking (or other types of networking) works
>> > that once you get that understanding it becomes a lot simpler.
>>
>> I still don't really understand it.  For example, why does the dom0
>> loose network connectivity when you add the physical interface through
>> which it is connected to the network to a bridge?  The bridge supposedly
>> connects networks indiscriminately, and it is illogical that the
>> connection goes away when you connect a network to it.
>>
>
> Knowledge of what a network bridge would help you clarify that question. [2]
> When you hook an interface to a Linux bridge the interface cannot be used
> for anything else [0].  That is why IP addresses are instead placed on the
> bridge interface [1].

I never came across information like that.  I was trying to get network
access for VMs to work, and that is just way too difficult.

> I prefer to segregate management and VM physical interfaces.  One interface
> is strictly used for managing the virtualization node and the other(s) are
> for VMs.  Those others could be hooked to different Linux bridges (cabled
> to your physical switch) or bonded together.  I do not have (nor need) IP
> addresses on bridges with my set up.

But when you attach them to bridges and don't have IP addresses on the
bridges, then they are unreachable.


-- 
Knowledge is volatile and fluid.  Software is power.