The Isilon Gen 6 platform provides a single 1 GbE interface per node. The original intent of the interface was to provide SSH access to the cluster. However, against best practice, many cluster configurations use these interfaces for data access, either intentionally or unintentionally.
The 1 GbE interface was not designed for data transfer because the chipset does not support TCP Segmentation Offload (TSO) and Large Receive Offload (LRO), increasing the chances of dropped packets, port flapping, and other performance issues. TSO and LRO are available on the 10 GbE and 40 GbE ports, which are optimized for data traffic.
Note: The 1 GbE interfaces on Isilon Gen 6 nodes should not be used for data transfer under any circumstances. During the initial cluster configuration, if possible, do not configure the 1 GbE interface. If the interface must be enabled, it should only be used for WebUI and SSH access.
As a best practice, the 1 GbE interfaces should not be configured. During the initial cluster configuration, only configure the 10 GbE and 40 GbE interfaces. If the 1 GbE interface must be used for the initial cluster configuration, after the cluster is configured, remove the 1 GbE interfaces from all IP pools.
If the 1 GbE interfaces must be configured:
Clusters using the 1 GbE interfaces for anything other than WebUI and SSH access experience overall performance degradation. Protocol performance suffers if traffic is routed through the 1 GbE interface. SyncIQ reports random failures because it might communicate through the 1 GbE interfaces, even if a policy is configured not to use those interfaces. Performance degradation might also affect authentication, SRS, CEE, anti-virus, and CloudPools.
Another factor to consider for leaving the 1 GbE interface unconfigured is that starting with OneFS release 8.0, the bge driver for the 1 GbE interface increments InputDiscards for unwanted packets, such as multicast and spanning-tree packets. The InputDiscards show as errors under the netstat -in command, complicating the cluster network monitoring.