Internal and external networks

A cluster includes two networks: an internal network to exchange data between nodes and an external network to handle client connections.

Nodes exchange data through the internal network with a proprietary, unicast protocol over InfiniBand or Ethernet, depending on the node model. Each node includes redundant InfiniBand or Ethernet ports for a second internal network in case the first port fails. Ethernet is the only supported external network.

Supported network configurations are as follows:

  • Generation 5 nodes support only InfiniBand for the internal network.
  • PowerScale nodes support 10 GB and 40 GB Ethernet, with 25 GB Ethernet as a later add-on option.
  • PowerScale F200 supports 10 GB and 40 GB Ethernet and InfiniBand.
  • PowerScale F600 supports 10, 25, 40, and 100 GB Ethernet, and10, and 40 GB InfiniBand.

PowerScale , and PowerScale nodes support InfiniBand and Ethernet for the internal network. You can mix Generation 5, PowerScale, and PowerScale F200 and F600 nodes in the same cluster. PowerScale F200 and F600 nodes support only an Ethernet internal network.

NOTE: Ethernet is recommended for the internal network. However PowerScale F200 and F600 nodes do support InfiniBand options for existing InfiniBand clusters.

Clients reach the cluster using Ethernet. Since every node includes Ethernet ports, the cluster bandwidth scales with performance and capacity as nodes are added.

CAUTION:  Only Isilon or PowerScale nodes should be connected to the internal network, depending on the node model. Information that is exchanged on the back-end network is not encrypted. Connecting anything other than Isilon or PowerScale nodes to the internal network creates a security risk.