[ovirt-users] how does ovirt deal with multiple networks, with multiple gateways

[Charles Tassell]

Hi Martin,

   oVirt 4.1 (and maybe earlier versions that I just didn't notice) use 
policy based routing.  You can see these routes by typing "ip rule show" 
on one of the hosts.

   In situations such as yours, where you are connected to multiple 
networks and need to specify which one has the gateway, there is a 
little trick you need to use on the admin box (usually the hosted engine 
VM, it' sthe same box that runs the GUI)  ssh into that box and then run 
the following two commands:

   engine-config -g UserDefinedNetworkCustomProperties
   engine-config -s 
UserDefinedNetworkCustomProperties='default_route=^(true|false)$'

Next, go into the GUI and onto the Hosts tab.  Click on your first host 
then on the Network Interfaces tab, and "Setup Host Networks"  Click on 
the little pencil icon next to your VM network (the one that should have 
the default route) and then on the Custom Properties tab.  Add the 
property "default_route" and set it to true and hit OK.  Then click on 
all of the other networks you have and add the same property with the 
value of false.  Then hit OK to save the network config.  Repeat this 
process for all hosts.

Note that I think when I did this I had a problem getting it to save for 
the host that was running the HostedEngine.  You may have to put each 
host into Maintenance Mode in order to apply the setting.

This bug has some more details on the setup I think: 
https://bugzilla.redhat.com/show_bug.cgi?id=1400366



On 2017-04-30 09:00 AM, users-request at ovirt.org wrote:
> Message: 1
> Date: Sun, 30 Apr 2017 13:03:28 +0200
> From: martin chamambo <chamambom at gmail.com>
> To: Yaniv Kaul <ykaul at redhat.com>
> Cc: users <users at ovirt.org>
> Subject: Re: [ovirt-users] how does ovirt deal with multiple networks
> 	with multiple gateways
> Message-ID:
> 	<CAHbWOdZRBsTuqWKTzU6Aa4e=e1RXH30fQpg58dT3mOVWZgVAKg at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> I am using ovirt 4.1.1.X.X  version on both nodes and Engine.
> There are no static routes and the network topology is is such a way that
> only the VMnetwork logical network is on a network with internet and has
> got  a default gateway .
>
> so i have
> 192.168.1.X  with a gateway of say 192.168.1.50 (This has internet) and
> this is the VM network
>   192.168.2.X , no gateway and is the ovirtmangnt
> 192.168.3.X  no gateway and its the display
> ,192.168.4.X , no gateway and its the Migration network
> 192.168.5.X , no gateway and its the Storage
>
> when i set up these networks using the Ovirt engine GUI , ovirt seems to
> create routes and rule files for each specific network ,but for some reason
> , i cant ping anything besides the networks defined
>
> On Sun, Apr 30, 2017 at 8:45 AM, Yaniv Kaul <ykaul at redhat.com> wrote:
>
>> Can you share some more details?
>> - What version are you using?
>> - What is the network topology? Are any static routes defined? The fact
>> oVirt sets a specific network for storage does not imply it'll use it for
>> storage automatically - unless routing is properly defined for it.
>>
>> TIA,
>> Y.
>>
>> On Sun, Apr 30, 2017 at 8:11 AM, martin chamambo <chamambom at gmail.com>
>> wrote:
>>
>>> Hello
>>>
>>> I am testing ovirt and i have configured it with 5 networks as shown
>>> below
>>>
>>> Display , Migration , VMnetwork ,Storage and the default ovirtmngmnt
>>> network
>>>
>>> These networks are represented by individual phyiscal interfaces on the
>>> ovirt nodes and for some reason the default gateway is not being set
>>> correctly
>>>
>>> it always seem to prefer the ovirtmngmnt interface as the default
>>>
>>> The only network thats supposed to have internet is the VMnetwork role
>>>
>>>
>>> _______________________________________________
>>> Users mailing list
>>> Users at ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/users
>>>
>>>