Use the hpvmnet -h command to halt the vswitches.
For example:
# hpvmnet -S clan1 -h
hpvmnet: Halt the vswitch 'clan1'? [n]: y |
Auto Port Aggregation (APA) can be configured on the VM Host to provide
a highly available LAN for the vswitch (APA in active/passive mode) or to
increase the bandwidth of the vswitch LAN (APA active/active mode). Before
you stop APA, halt the vswitches associated with it. If you do not bring down
the vswitch first, the hpvmnet command reports an incorrect
MAC address for the vswitch.