VNX5400 host disappeared

Good day.

VNX 5400; 05.33.008.5.119, Windows 2012 R2 with qlogic hba.

I got some problem with Windows host: sometimes it is not displayed in the host list in the Unisphere. However there are no real problem with storage access, this Winddows host works fine as veeam backup direct SAN access proxy (backing up VMs directly from VMFS volumes that reside on VNX LUNs).

Unisphere host agent is installed on this Windows host (7.33.9.1.84), here is the config:

clarDescr clarContact poll 60 baud 9600 eventlog 2048 User system@10.12.0.51 User system@10.12.0.52

10.12.0.51 and 10.12.0.52 are the real IPs of VNX SPs.

I`ve tried to launch the agent and to reboot this host, but it seems that the problem occures randomly.