Network Layout

The network structure/topology in a cluster may be the most important design decision. There are countless options, but the most relevant options are covered here.

Single Network

This is the simplest network layout you can plan for a cluster. The head node has only one network interface and all the compute nodes are on the same network. Please note that the head node will still be serving DHCP on the network, so you need to disable DHCP on all routers/switches.

Enclosed Compute Network

In this setup, the head node has two network interfaces and is attached to two separate switched networks:

• A publicly available network; users will connect to the head node through it. You do not need to disable DHCP on this network.
• A closed network on which all the compute nodes are located. The head node acts as a DNS/DHCP server on this network, but not as a gateway. If you want to enable NAT or routing, you will have to do it manually. Please note there might be some firewall issues as well. You will need to remember which interface is connected to the compute network.

Split Compute/Management Networks

In this design the compute nodes communicate to each other on a separate physical network (compute network) from the one they use to speak to the head node (management network). This kind of layout is not directly supported by the wizard and requires additional manual configuration.

Infiniband

Infiniband is currently supported at kernel level, but the OpenFabrics Enterprise Distribution (OFED) userspace utilities are not distributed and must be manually installed.