Which module allows for communication between different nodes in an OpenStack environment?

In an OpenStack environment, the module responsible for enabling communication between different nodes is Neutron. Neutron is the networking component of OpenStack, which provides a range of networking services to manage the network connectivity between instances (virtual machines) and enables them to communicate with one another as well as with external networks.

Neutron allows users to create virtual networks, subnets, and routers, and it supports various network services such as load balancing, firewalls, and VPNs. By facilitating these functions, it ensures that instances can communicate seamlessly whether they are on the same network or across different networks, making it essential for any cloud deployment that requires complex network configurations.

The other modules mentioned serve different purposes: Cinder is for block storage, Ironic manages bare metal servers, and Swift is used for object storage. Each of these modules provides important functionalities but does not focus on inter-node communication, which is the primary role of Neutron.