VPLEX VS6 MMCS can't connect all directors

My VPLEX VS6 cannot connect all directors.

#VPlexPlatformHealthCheck -v Output is this.

service@ManagementServer:~> VPlexPlatformHealthCheck -v
System Information
------------------
     dual engine(medium config)system detected

Management Server IP Connectivity Check
---------------------------------------
     Error issuing ping command for ip 128.221.252.35
     Error issuing ping command for ip 128.221.252.36
     Error issuing ping command for ip 128.221.252.37
     Error issuing ping command for ip 128.221.252.38
     Error issuing ping command for ip 128.221.253.35
     Error issuing ping command for ip 128.221.253.36
     Error issuing ping command for ip 128.221.253.37
     Error issuing ping command for ip 128.221.253.38
     Error issuing ping command for ip 128.221.253.33
     Error issuing ping command for ip 128.221.254.67
     Error issuing ping command for ip 128.221.254.68
IP interfaces : OK
     All interfaces are UP
Discover Network Devices : ERROR
     Missing IP address of Directors : 128.221.252.35
         Make sure IP is configured on Directors
     Missing IP address of Directors : 128.221.252.36
         Make sure IP is configured on Directors
     Missing IP address of Directors : 128.221.252.37
         Make sure IP is configured on Directors
     Missing IP address of Directors : 128.221.252.38
         Make sure IP is configured on Directors
     Missing IP address of Directors : 128.221.253.35
         Make sure IP is configured on Directors
     Missing IP address of Directors : 128.221.253.36
         Make sure IP is configured on Directors
     Missing IP address of Directors : 128.221.253.37
         Make sure IP is configured on Directors
     Missing IP address of Directors : 128.221.253.38
         Make sure IP is configured on Directors
     Missing IP address of SMS : 128.221.253.33
         Make sure IP is configured on SMS
     Missing IP address of BMC : 128.221.254.67
         Make sure IP is configured on BMC
     Missing IP address of BMC : 128.221.254.68
         Make sure IP is configured on BMC
IP Connectivity to Directors Check : OK
     Connectivity through subnet 128.221.252:
     Connectivity through subnet 128.221.254:
Please refer connectivity section of the Platform HealthCheck troubleshooting guide.

Local-com IB Connectivity Check
-------------------------------
     ERROR: [Errno 113] No route to host
Please refer connectivity section of the Platform HealthCheck troubleshooting guide.

Engine configuration Check
--------------------------

Management Server System Check
------------------------------
Process Check : ERROR
     Process ipsec: Checking for service strongSwan IPsec ..unused
Check Partitions : OK
     Partition is OK
CPU Check : OK
     number of CPUs 4
Configuration Files Presence Check : OK
     Required files are present
Please refer software section of the Platform HealthCheck troubleshooting guide.

In all MMCS. Ping all directors(128.221.252.35~38) is unreachable

I trying to change MMCS1 and MMCS2 and reboot VPLEX.

Than it didn't work too.

I think MMCS between Directors has problem.

What can i do for my VPLEX?

I need how to login any director like serial port in VNX, VPLEX VS2

and I want reset my director, MMCS. all of my VPLEX

Help..