I configured ext-net, private-net, vm and FIP on a setup (3 node) and all worked OK.
I deleted everything (including ext-net) and re-created all of it but this time the FIP is not pingable.

Analysis:
ietf-state deleted prior to vpn-interface delete

on vpn-interface delete
--------------------------

2017-03-14 09:15:34,276 | INFO | pool-31-thread-1 | NeutronvpnManager | 341 - org.opendaylight.netvirt.neutronvpn-impl - 0.3.2.R1_0-SR2 | Removing vpn interface 189422603837786:br-physnet1-pa:flat

2017-03-14 09:15:34,556 | INFO | pool-31-thread-1 | VpnInterfaceManager | 337 - org.opendaylight.netvirt.vpnmanager-impl - 0.3.2.R1_0-SR2 | VPN Interface remove event - intfName 189422603837786:br-
physnet1-pa:flat
2017-03-14 09:15:34,558 | ERROR | pool-31-thread-1 | VpnInterfaceManager | 337 - org.opendaylight.netvirt.vpnmanager-impl - 0.3.2.R1_0-SR2 | Unable to retrieve interfaceState for interface 189422603837786:br-physnet1-pa:flat , quitting

on new vpn-interface creation
--------------------------------

2017-03-14 09:54:55,008 | INFO | nPool-1-worker-1 | VpnInterfaceManager | 337 - org.opendaylight.netvirt.vpnmanager-impl - 0.3.2.R1_0-SR2 | vpn interface 189422603837786:br-physnet1-pa:flat to go to configured vpn 4c91304a-49dd-4ce9-96b5-418200bf3368, but in operational vpn 98b3e8d5-7f70-4233-89d0-69fac541dfbd

5-418200bf3368
2017-03-14 09:54:55,027 | ERROR | pool-31-thread-1 | FlowBasedServicesConfigListener | 328 - org.opendaylight.genius.interfacemanager-impl - 0.1.2.R1_0-SR2 | Service Binding entry update not allowed for: 189422603837786:br-physnet1-pa:flat, Data: BoundServices{getServiceName=vpn.4c91304a-49dd-4ce9-96b5-418200bf3368.189422603837786:br-physnet1-pa:flat, getServicePriority=5, getServiceType=class org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.ServiceTypeFlowBased, augmentations={interface org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.StypeOpenflow=StypeOpenflow{getFlowCookie=134217729, getFlowPriority=10, getInstruction=[Instruction{getInstruction=WriteMetadataCase{getWriteMetadata=WriteMetadata{getMetadata=140002, getMetadataMask=4294967294, augmentations={}}, augmentations={}}, getOrder=1, augmentations={}}, Instruction{getInstruction=GoToTableCase{getGoToTable=GoToTable{getTableId=19, augmentations={}}, augmentations={}}, getOrder=2, augmentations={}}]}}}