VMware Backups fail with Status 23 / 6 after upgrading Appliance to 3.1 / 3.1.1

Problem

VMware backups stop working after the Appliance is upgraded to version 3.1 / 3.1.1. The backup also continues to run for an extended amount of time after the actual failure.

Error Message

Error opening the snapshot disks using given transport mode: san:nbd:nbdssl Status 23
FTL - cleanup() failed, status 6
unexpected termination of client "CLIENTNAME"
status: 6: the backup failed to back up the requested files

VXMS LOG shows (The log has been scrubbed):
  [VFM_ESINFO] NBD_ClientOpen: attempting to create connection to vpxa-nfc://[ST_EMC_XXX_XXX] VM-02/VM-02_2.vmdk@XX.XX.XX.XX:902
  [VFM_ESINFO] [NFC DEBUG] Using proxy/session authentication, sessionId=52 a2 be 0f b6 f7 45 34-57 d0 c8 f0 c0 ef 1a 42, useSSL=0
  [VFM_ESINFO] [NFC INFO] Plain-text connection is deprecated; use SSL to connect to NFC server
  [VFM_ESINFO] SSL: syscall error 104: Connection reset by peer
  g_vixInterfaceLogger:libvix.cpp:1804 <DEBUG> : [VFM_ESWARN] SSL: connect failed (5)
  [VFM_ESINFO] CnxAuthdConnect: Returning false because SSL_ConnectAndVerify failed
  [VFM_ESINFO] CnxConnectAuthd: Returning false because CnxAuthdConnect failed
  [VFM_ESINFO] Cnx_Connect: Returning false because CnxConnectAuthd failed
  [VFM_ESINFO] Cnx_Connect: Error message:
  g_vixInterfaceLogger:libvix.cpp:1804 <DEBUG> : [VFM_ESWARN] [NFC ERROR] NfcNewAuthdConnectionEx: Failed to connect to peer. Error:
[VFM_ESINFO] NBD_ClientOpen: Couldn't connect to XX.XX.XX.XX:902

Cause

It is not clear if this is an issue between the switch and Appliance or if something has changed on the bond after the upgrade, but the result is an SSL error in the communication between VMware and the Appliance.

Solution

It may be found that other appliances also at version 3.1.1 are able to back up the virtual machines.

Otherwise:

1. Make sure to capture the bond configuration from the clish menu, but the IP configuration should automatically be added to the default NIC on the Appliance:
     Appliance.Network>Show Properties

2. Unconfigure bond and reconfigure bond from the appliance's CLISH
   
3. The backup should start working right after the bond is reconfigured.