OpenStack Interview Questions And Answers Set-9

81. How Can You Create A Token?

Users first need to authenticate their Keystone credentials to create a token

82. What Is Contrail?

Contrail is a project that implements network virtualization as an overlay network compatible with existing IETF standards. It is an implementation of the Neutron API that provides distributed routing and interoperability with network appliances.

83. Does Contrail Work In Headless Mode? Basically, I Want To Know What Is Going To Happen To VMS Traffic If The Three Config/control Nodes Are Gone.

Yes. The Contrail compute node components can work in case all the control-nodes became unavailable. Likewise, the control nodes can continue to operate in case all the config nodes become unavailable. Components are designed to operate in active-active mode.

84. Will I Need Juniper Kit To Run Contrail? If I Do What Kit? L2/l3 Switches Or A Router?

No. You can run Contrail without Juniper network gear. The switching gear just needs to be able to pass IP packets. For gateway between overlay and external networks, you can use the software gateway included in Contrail or any L3VPN-compatible appliance that supports MPLS over GRE.

85. Does Contrail Require Juniper Switches Or Is It Compatible With Other Vendors’ Hardware?

No, Contrail does not require Juniper hardware (or any specific hardware unless anticipated traffic requires the additional throughput of a hardware solution). Mirantis and Juniper customers are presently working with several clients in production with non-Juniper hardware. The Mirantis/Juniper Reference Architecture contains instructions for configuring both Juniper and Cisco example hardware.

86. What Is The Main Differentiation For Contrail Compared To Nsx?

Dynamic routing. Contrail is built around the concept of being able to federate clusters managed by potentially different admin authorities via BGP. That is what it uses to federate its control-nodes internally and to interoperate with existing L3VPN network equipment.

87. Is It Possible To Run OpenStack In Ipv6-only Mode Using Opencontrail, I.e., No Ipv4 At All, Neither In The Underlay Nor The Overlay Network?

No. Contrail implements an IPv6 overlay. No plans at the moment to work on an IPv6 underlay.

88. Do We Need To Have Hardware In The Datacenter That Understands Mpls/bgp/l3vpn? Dc Won’t Have Them As These Are Wan Technology/protocols?

There is a software gateway implementation that is provided as part of Contrail. It becomes more efficient to use hardware appliances once you cross a certain threshold of external traffic (e.g. 10G).

89. What Does Contrail Offer That Neutron Is Not Already Providing Today?

Dynamic routing and service chaining. We also believe that it is a more scalable implementation when compared to the reference implementation.

90. If You Already Have A Mirantis Distro, Do You Have A Cookbook To Get Contrail On The Current Installation?

We developed internal runbooks for integrating earlier versions of Contrail/OpenContrail components to Mirantis OpenStack 5 (Icehouse), but these are now deprecated and not supported.