VLAN guest tagging (vgt) possible in RHEV 3.0?

Latest response

Hi all,

 

I'm in the process of transitioning a data processing system from vmware esxi 5.1 to rhev 3.0.  In vmware I have private data network that is asigned vlan id 4095.  I'm having difficulty in getting the equivalent network set up in rhev, it seems it does not like vlan id 4095. 

 

What I have tried is this:

 

1. Create a new logial network in my datacenter with vlan tagging enabled, using vlan id 4095.

2. Attach the logical network to my cluster

3. For each host in the cluster, assign an interface (eth6 in my case) to the new logical network

4. On each VM, create a vlan (eth2.507 in my case)

 

When I do this, my VMs cannot communcate over vlan 507.

 

What is the correct way to implement vgt in rhev, if it's possible at all?

 

On a side note, with all my rooting around trying to get this to work over the last few days, I've ended up with multiple (and no longer needed) interface config files in /etc/sysconfig/network-scripts/ on each of my cluster hosts.  When I try to delete them, I get a "file is in use" error, even though the interface is down.  How do I clean up (delete) these config files?

 

Cheers,

Steve.

st
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Responses

DY Guru 5340 points
1 November 2012 4:05 PM

Hi,

 

VLAN 4095 is reserved and shouldn't be used (RFC 5517), this is why it is blocked.

As for the config file removal, I'm afraid you will need to either rebuild the host or open a support ticket asking for assistance with this. You should not have any extra config files, and if you tamper with a hypervisor's config, it is not easy to get things back to normal without reinstalling or going into the system's sosreports and investigating. Unfortunately deep log dives are not easy to do here in the groups, support tickets are better equipped to deal with those

 

st Active Contributor 245 points
1 November 2012 4:41 PM

Thanks Dan.

 

So are you saying that RHEV specifically does not allow vlan 4095?  I know it's reserved per the RFC, but vmware seem to get away with using it.  I'm seeing an error in rhevm.log when interface eth6.4095 is being activated, something along the lines of:

 

RTNETLINK answers: Numerical result is out of range.

 

Any suggestions on how to implement vlan guest tagging in rhev, given that it seems I can't use vlan id 4095 (which is how vmware do it)?

 

-Steve.

 

 

 

 

DY Guru 5340 points
1 November 2012 4:48 PM

RHEV and the Linux kernel both. 

 

If you want all the VMs to be tagged with a specific VLAN, you create a logical network with that VLAN, and then attachyour guests to this network, that's all.

Alternatively, you can also do the tagging inside the VMs, attaching them to a non-tagged network

st Active Contributor 245 points
1 November 2012 7:39 PM

Thanks Dan, turning off vlan tagging on that network solved the problem.  I should have mentioned in my first post that I'm handling the vlan tags on the VM.

 

-Steve.

DY Guru 5340 points
1 November 2012 9:41 PM

Glad it worked out for you Steve. It always helps to keep in mind that RHEV is not a copycat of other virtualization platforms. Usually, as we have tried to make them, things are simpler and more intuitive in RHEV, and there is no sense in trying to follow recipes from other platforms here.

If you're tagging int he VMs, there's no point tagging on the hosts as well, inless you want vlans encapsulated in other vlans (I know some ISPs do that).

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