Multicast
Optimized fast branch updates (PTX10001-36MR, PTX10004, and PTX10008)—Starting in Junos OS Evolved Release 21.3R1, we've refined the current method of fast-branch updates to the multicast replication tree. Now, any membership changes in the tree (such as joins and deletes) trigger fast make-before-break re-optimization of the tree to ensure that there is no traffic loss.
[See Multicast Shortest-Path Tree.]