that's strange, we reconfigure connection betwen cluster and dss.
old configuretion:
dss have two 10gb network adapter.
every adapter has network address 192.168.150.1/24 and 192.168.160.1/24
both adapter connected to switch in vlan 300.
every nodes in cluster have one network adapter and two ip address:
192.168.150.11.../24
and alias ip address 192.168.160.11.../24
we disconnect one network adapter on dss in gui and after one minutes cluster work fine.