Hi Daniel, Yes you could do .1q at an interface level for the VR ( this is what we do with KVM networking ). However this brings you a couple of stumbling blocks:
1) For you to trunk VLANs to this interface it would need to be attached to a trunked vSwitch – which is currently all or nothing in VMware (by setting vlan for the vSwitch to 4095) – i.e. you can’t set a vSwitch to only trunk certain VLAN ranges. This now brings you a further problem – if you did trunk at the vSwitch level you would have to configure your top of rack switches to do the same. Again – this is possible – but when you consider that you *must* be able to isolate all VLAN traffic on a per CloudStack account level – this would mean you would need one or more ESXi physical NICs per account + a considerable count of top of rack physical switch ports. So – you are effectively moving the problem from the virtual switches to the physical ones, which while technically possible is not feasible. 2) Your main problem is at the user VM end. If we agree you can’t expect VLAN tags to be set at the guest OS level then the only other place to set this is at the vSwitch level. Keeping in mind the limitations mentioned above this means you need at least one vSwich ( = VLAN ) per VPC tier. Since there is no way other than the all-in trunking mentioned above for the VPC VR to connect to all of these tier vSwitches implementing .1q at the VR level would not work. Keep in mind though – my points above are purely in the context of VMware and VLANs – as soon as you step into the SDN world you move to overlay networks etc where other mechanisms could be and are implemented. = = Dennis – to answer your question as well – CloudStack speaks to XenServer using the API. I think you have probably answered your own question though – as you pointed out in your discussion forum thread all documentation says 7 NICs is the max supported. If you do some testing and find the API can handle more than 7 then I would suggest to log a Jira ticket such that this can be implemented in future CloudStack versions. Regards, Dag Sonstebo Cloud Architect ShapeBlue On 15/08/2017, 14:10, "daniel.herrm...@zv.fraunhofer.de" <daniel.herrm...@zv.fraunhofer.de> wrote: Hi Dag, you would need to do that with the Linux dot1q kernel module, yes. This way you can create virtual interfaces with VLAN tags and bind them to one NIC. We are routing and firewalling in software anyway, I do not see any considerable additional overhead here. Instead of “physical” NICs, we have one of them and create the other as VLAN interface. I do not really understand the security problems as well. No user is ever expected to have access to the virtual router. So how would that affect security? Regards Daniel Am 15.08.17, 14:36 schrieb "Dag Sonstebo" <dag.sonst...@shapeblue.com>: Hi Daniel, The mechanism for isolating L2 traffic is at the vSwitch level – there is no way to VLAN tag the at the NIC level for a VM in VMware. Your only other option is therefore to VLAN tag at the guest OS level which adds security issues + overhead, etc. Regards, Dag Sonstebo Cloud Architect ShapeBlue On 15/08/2017, 13:05, "daniel.herrm...@zv.fraunhofer.de" <daniel.herrm...@zv.fraunhofer.de> wrote: Hi Dag, thank you for your answer. As far as I know, the end user never has direct access to the virtual router. I am not talking about adding a VLAN tag at the user VM, only at the VPR, where the limit most likely comes into play when creating a number of tiers in a VPC. We could do both: normal VMs require one interface per tier/network, which makes perfect sense. The router however could use VLAN tags at VM level, which could remove the limitation of having a maximum number of tiers connected to one VPC. It is only configured by CloudStack, the end user does not have access to the VPR. Regards Daniel Am 15.08.17, 13:27 schrieb "Dag Sonstebo" <dag.sonst...@shapeblue.com>: Hi Daniel, In theory that could work – but keep in mind we are working in a multi-tenant environment, where guest isolation must be guaranteed, hence cannot ever be exposed to normal users. The isolation method must be abstracted from the end user VMs – otherwise you would have a potential security issue where someone could tag traffic from their VM with someone else’s tag. Doing tagging at VM level would also be a huge overhead. As a result we VLAN tag at the vSwitch or bridge level – which end users have no access to – the flipside of the coin being that this requires separate NICs for each tier. Regards, Dag Sonstebo Cloud Architect ShapeBlue On 15/08/2017, 11:07, "daniel.herrm...@zv.fraunhofer.de" <daniel.herrm...@zv.fraunhofer.de> wrote: Hi, we are hitting the same limitation, except that we can use 10 NICs on VMware. The fact that we also use the Private Gateway functionality addes another NIC, besides the management and outside NIC which is present as well. I wonder that is the reason for one NIC per tier? Why not just use one outside NIC, one management NIC and *one* NIC for the tiers, where the VLANs (or whatever isolation method is used) is trunked, for example just using subinterfaces and dot1Q tags? This would eliminate this limit for whatever hypervisor that supports trunk to it’s guests (I know for sure about VMWare, not so much about the other hypervisors). Regards Daniel Am 15.08.17, 10:52 schrieb "Dag Sonstebo" <dag.sonst...@shapeblue.com>: Hi Dennis, Any tier or network which is accessible and part of a VPC requires an interface on the VPC Virtual Router. What you can however do is create separate shared networks and connect these as secondary networks to your VMs – these shared networks get their own VR. Regards, Dag Sonstebo Cloud Architect ShapeBlue On 15/08/2017, 09:19, "Dennis Meyer" <snooop...@gmail.com> wrote: Hi, im using xenserver as hypervisor so im limited to 7 nic's / vm, so the router vm cant handle more than 7 nics which corresponds to 7 networks inside a vpc. I had created some networks for different drbd and corosync stuff, they dont need a gateway, dhcp and a router vm. How should a network offering look like which dont creates a network on the routervm but is accessible by the vpc? Snooops dag.sonst...@shapeblue.com www.shapeblue.com 53 Chandos Place, Covent Garden, London WC2N 4HSUK @shapeblue dag.sonst...@shapeblue.com www.shapeblue.com 53 Chandos Place, Covent Garden, London WC2N 4HSUK @shapeblue dag.sonst...@shapeblue.com www.shapeblue.com 53 Chandos Place, Covent Garden, London WC2N 4HSUK @shapeblue dag.sonst...@shapeblue.com www.shapeblue.com 53 Chandos Place, Covent Garden, London WC2N 4HSUK @shapeblue