The Nova network service, also known as neutron, manages networking for all instances within an OpenStack environment. Neutron offers a standard way to provide network connectivity between instances and external networks, and it also supports advanced networking features such as virtual private networks (VPNs), firewalls, and load balancing.
Components of the Nova Network Service
The Nova network service consists of several key components:
- Neutron Server: The Neutron server is the central component of the network service and manages the creation, deletion, and modification of networks, subnets, and ports.
- Neutron Agents: Neutron agents are deployed on each compute node and manage the actual networking configuration on the node. There are several types of Neutron agents, including:
- L3 agent: The L3 agent is responsible for managing IP addresses and routing traffic between instances.
- DHCP agent: The DHCP agent provides DHCP services to instances.
- Metadata agent: The metadata agent provides instances with metadata such as the instance's name and IP address.
- Networking Plugins: Neutron supports several networking plugins that provide specific networking implementations. Some popular plugins include:
- Linux Bridge: The Linux Bridge plugin uses Linux bridges to connect instances.
- Open vSwitch: The Open vSwitch plugin uses Open vSwitch to connect instances.
- VMware NSX: The VMware NSX plugin uses VMware NSX to connect instances.
Networking Concepts in Neutron
Neutron uses the following networking concepts:
- Network: A network is a logical grouping of interconnected instances.
- Subnet: A subnet is a subdivision of a network and represents a range of IP addresses that can be assigned to instances.
- Port: A port is a logical point of attachment for an instance to a network. Each instance has at least one port.
- Security group: A security group is a set of rules that control which network traffic can be sent to and from instances.
Using the Neutron API
The Neutron API is used to manage networks, subnets, ports, and security groups. The API can be used directly or through the OpenStack CLI (nova).
