This object indicates the way to configure the LDP policy of vpn instance for LDP Auto FRR.
Options:
1. all(1) -indicates that all FECs are triggered for the IGP.
2. none(2) -indicates that no FEC is triggered for the IGP.
3. host(3) -indicates that the host FEC is triggered for the IGP.
4. ipprefix(4) -indicates that the ip-prefix list is triggered for the IGP.
If the object is set as ipprefix, the value of hwMplsVpnFrrLspTriggerIpPrefix must be set together.