How do PE routers operate with the MDT in a multicast VPN?

When the sending PE router recognizes that multicast data has exceeded the bandwidth threshold, it creates a data MDT and sends a UDP message to all routers using the default MDT.

After the default MDT and BGP VPNv4 neighbor is configured, a different PE neighbor in the IPv6 MDT address family is configured automatically for migrating to MDT SAFI.

When the source PE router establishes adjacency using PIM SM mode in the default MDT, the receiving PE requests information about the source PE for BGP advertisement.

The default MDT uses PIM sparse mode and PIM establishes adjacency over the shortest path tree toward the destination PE router.