Description of the feature request: =================================== As part of the Neutron integration we would like to leverage the ability to utilize Overlay Networks with GRE and VXLAN as the encapsulation protocol, instead of using 802.1Q VLANs to isolate VM traffic. Both GRE and VXLAN are supported by Open vSwitch, thus the Open vSwitch resides on the hypervisors can act as the software termination of the overlay tunnels. There are two main use cases for RHEV: 1) Isolated logical networks - The VM end-point, once configured on an overlay segment, cannot communicate with any other non-overlay network. This can be used to provision "isolated" logical network that can provide internal L2 connectivity to VMs running on different hypervisors. This is a capability we don't have today, where anything related to host-to-host communication must involve VLAN configuration and interaction with the hardware switches as well. Note that in this use case no external connectivity is required. 2) A replacement for VLAN in the DC - In this use case the overlay networks will be used instead of 802.1Q VLAN to isolate VM traffic in the environment. The main benefits here are: - Hypervisors are no longer need to be located on the same VLAN/IP subnet - Minimum interactions is required with the physical network infrastructure - The 4K scale limitation of VLAN is gone The challenge here is how to provide external connectivity to the VMs which resides within the overlay network. As stated in the first use case described above, the VM end-point, once configured on an overlay segment, cannot communicate with any other non-overlay network. This requires a GW device that should be able to encapsulate and decapsulate the overlay header and translate it to native IP/802.1Q VLAN in order to communicate with non-overlay networks/existing devices in the DC. This can be achieved by introducing virtual L3 routers that will serve as D.G for the VMs and will handle the connectivity with anything outside of the overlay.
Preliminary info can be found in this link: http://www.ovirt.org/OVirt_Neutron_GRE_Integration_-_How_To which shows how to manually implement the first use case (isolated logical networks) using the current integration bits. This RFE should bring full support of the feature, including the option to configure and monitor the networks from within the Web Admin UI.
*** Bug 1061209 has been marked as a duplicate of this bug. ***
Closing old RFEs, please reopen if still needed. Patches are always welcomed.