OpenStack OpenStack Networking (Neutron) 2 — Questions and Answers
Question 1: Which Neutron plug-in mechanism uses software-defined networking (SDN) with virtual switches?
- LinuxBridge ML2 driver
- Open vSwitch (OVS) ML2 driver (Correct answer)
- MACVLAN driver
- SR-IOV driver
Correct answer: Open vSwitch (OVS) ML2 driver
The Open vSwitch (OVS) ML2 driver is a widely used Neutron mechanism driver that leverages OVS for virtual switching.
Question 2: What does ML2 stand for in the context of Neutron's plugin architecture?
- Multi-Layer 2
- Modular Layer 2 (Correct answer)
- Managed Linux 2
- Multi-Link 2
Correct answer: Modular Layer 2
ML2 stands for Modular Layer 2, a framework that allows OpenStack Neutron to use multiple Layer 2 technologies simultaneously.
Question 3: In Neutron, what is a 'subnet' defined as?
- A virtual router connecting two networks
- A block of IP addresses and associated configuration assigned to a network (Correct answer)
- A physical NIC bond in the hypervisor
- A firewall zone separating tenant traffic
Correct answer: A block of IP addresses and associated configuration assigned to a network
A subnet in Neutron is a block of IP addresses (CIDR) with configuration like gateway and DNS assigned to a network.
Question 4: Which Neutron agent handles DHCP requests for VMs on tenant networks?
- neutron-l3-agent
- neutron-metadata-agent
- neutron-dhcp-agent (Correct answer)
- neutron-linuxbridge-agent
Correct answer: neutron-dhcp-agent
The neutron-dhcp-agent provides DHCP services for tenant networks by managing dnsmasq processes.
Question 5: What is VXLAN in the context of OpenStack Neutron overlay networks?
- A VLAN tagging extension for more than 4096 networks
- A tunneling protocol that encapsulates L2 frames in UDP to extend networks over L3 (Correct answer)
- A Neutron API extension for external network access
- A storage network protocol used by Cinder
Correct answer: A tunneling protocol that encapsulates L2 frames in UDP to extend networks over L3
VXLAN (Virtual Extensible LAN) encapsulates Layer 2 Ethernet frames within UDP packets, enabling large-scale overlay networks.
Question 6: What is the role of the Neutron metadata agent?
- It manages Neutron database metadata records
- It relays instance metadata requests from VMs to the Nova metadata API (Correct answer)
- It stores network topology metadata in Zookeeper
- It provides IPAM services to subnets
Correct answer: It relays instance metadata requests from VMs to the Nova metadata API
The neutron-metadata-agent proxies requests from VMs to the Nova metadata API, enabling instances to retrieve their configuration data.
OpenStack OpenStack Networking (Neutron) 2
Which Neutron plug-in mechanism uses software-defined networking (SDN) with virtual switches?