SystemIP is usually used for management purposes and, therefore, it may be needed to create services to a separate loopback interface. Because of security concerns, many operators do not want to create services to the systemIP address. See Figure: NG-MVPN setup via loopback interface and Figure: Intra-AS basic opaque FEC to loopback interface.
The first portion of this feature allows MVPN routes be advertised with a nexthop specific loopback.
This can be achieved via two methods:
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Having IBGP session to the loopback interface of the peer, and using the corresponding local loopback for local-address.
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Having IBGP session to the systemIP but using policies to change the nexthop of the AD route to the corresponding loopback interface.
After the AD routes are advertised via the loopback interface as nexthop, PIM generates an mLDP FEC for the loopback interface.
The preceding configuration allows an NG-MVPN to be established via a specific loopback.
It should be noted that this setup works in a single area or multi-area through an ABR.