I’ve installed quite a few new Isilon clusters in 2019. All of them are generation 6 clusters (H400, H500, A200), using the very cool 4-nodes-in-a-chassis hardware. Commonality among all these systems is an 1GbE management port next to the two 10GbE ports. While Isilon uses in-band management, we typically use those UTP ports for management: SRS, HTTP, etc. We assign those interfaces to subnet0:pool0 and make it a static SmartConnect pool. This assigns one IP address to each interface; if you do it right, these should be sequential.
Recent addition to my install procedure is to create some DNS A-records for those management ports. This makes it a bit more human friendly to connect your browser or SSH client to a specific node. In line with the Isilon naming convention, I followed the -# suffix format. So if the cluster is called cluster01, node 1 is cluster01-1, node 2 is cluster01-2, etc. However, it turns out this messes up your SyncIQ replication behavior!