Were these the result of a security scan of the cluster?  For any cluster hardening, it's recommended to engage Isilon Support with the criteria for assistance in hardening the cluster.     Attempts to lock it down as with any other FreeBSD box will most often result in preventing the system from communicating with itself.  As common criteria evaluations are evolving, it'd be best to obtain this information straight from Support and Engineering.
Can somebody please explain what the following services are and whether they can be locked down:  xxxx/tcp  xxxx/tcp  xxxx/tcp  xxxxxx/tcp  I have a co-worker who is concerned that, from a security perspective, these may be non-essential services that pose a risk.
Non-essential ports and services