Isilon: SyncIQ’s resync-prep job can fail with the error "Authentication with target failed" if the policy’s Force Interface flag is set to yes

SyncIQ's resync-prep job can fail with the error "Authentication with target failed" even when we do not have a password configured for the sync policy.
Errors:

Authentication with target failed, (policy name: test target: 10.118.160.38) SyncIQ policy failed. Authentication with target failed

However the policy's Force Interface flag is set to yes.

 ID: 51d400a9b44decc9f6c562bf2dea05b4
                       Name: test
                       Path: /ifs/data/test_other
                     Action: sync
                    Enabled: Yes
                     Target: 10.118.160.38
              Source Subnet: subnet0
                Source Pool: pool0
           Workers Per Node: 3
             Report Max Age: 1Y
           Report Max Count: 2000
            Force Interface: Yes

You can see following messages if you put the migrate logs in trace mode during resync-prep:

Messages on Primary Cluster:

orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81122]: primary[test:1264326133]: Sending AUTH_MSG to sworker
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81120]: primary[test:1264326133]: Generated secret of ed45e4c673a2d0bed579a568add169f0
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81122]: primary[test:1264326133]: Received SWORKER_STF_STAT_MSG from sworker
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81122]: primary[test:1264326133]: sworker_stat_callback
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81122]: primary[test:1264326133]: Sending SWORKER_STF_STAT_MSG to coord
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81121]: primary[test:1264326133]: Generated secret of ed45e4c673a2d0bed579a568add169f0
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81121]: primary[test:1264326133]: Sending AUTH_MSG to sworker
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81122]: primary[test:1264326133]: Received NOOP_MSG from sworker
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81122]: primary[test:1264326133]: Received ERROR_MSG from sworker
orca7215-1: 2010-01-24T09:42:13Z <3.7> orca7215-1(id2) isi_migrate[81122]: primary[test:1264326133]: Sending ERROR_MSG to coord
orca7215-1: 2010-01-24T09:42:13Z <3.6> orca7215-1(id2) isi_migrate[81122]: primary[test:1264326133]: Disconnect from sworker

Messages on Secondary Cluster:

2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61917]: secondary[test:1264326133]: /ifs/.ifsvar/modules/tsm/passwd missing or bad, no authentication
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61917]: secondary[test:1264326133]: Sending AUTH_MSG to pworker
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61918]: secondary[test:1264326133]: Generated secret of 64752e5bd6f05f3c883009e006ac5cf1
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61918]: secondary[test:1264326133]: Received AUTH_MSG from pworker
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61918]: secondary[test:1264326133]: auth_callback
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61918]: secondary[test:1264326133]: Sending ERROR_MSG to pworker
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61918]: secondary[test:1264326133]: 7 bytes left to be sent for NOOP_MSG
2017-02-03T03:55:56Z <3.2> Halfpipe8011-1 isi_migrate[61918]: secondary[test:1264326133]: Primary authentication failed
2017-02-03T03:55:56Z <3.2> Halfpipe8011-1 isi_migrate[61918]: Exiting on ilog(IL_FATAL)
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61915]: secondary[test:1264326133]: siq_target_states_set: Policy test updating job state from SIQ_JS_RUNNING to SIQ_JS_FAILED
2017-02-03T03:55:56Z <3.6> Halfpipe8011-1 isi_migrate[90611]: bandwidth: Read socket error: Connection reset by peer
2017-02-03T03:55:56Z <3.6> Halfpipe8011-1 isi_migrate[61915]: secondary[test:1264326133]: Coord disconnects from target_monitor for test
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61915]: secondary[test:1264326133]: siq_target_states_set: Policy test updating job state from SIQ_JS_FAILED to SIQ_JS_FAILED
2017-02-03T03:55:56Z <3.7> Halfpipe8011-1 isi_migrate[61915]: secondary[test:1264326133]: siq_target_states_set: Policy test changing cancel state from CANCEL_WAITING_FOR_REQUEST to CANCEL_DONE
2017-02-03T03:57:52Z <3.6> Halfpipe8011-1 isi_migrate[61963]: secondary: Disconnect from pworker (5)

A resync-prep attempts to connect to the local cluster over the internal IB network. This connection fails if the force interface flag is set to yes.

Flip the force-interface and retry resync-prep:

#isi sync policies modify --policy=<policyName> --force-interface=off