Lectures notes for 2010 - KTH

• RPF results in a different spanning tree for each source.
A
1
B
2
A
1
B
2
A
1
B
2
D
3
6
E
4
5
C
D
3
6
E
4
5
C
D
3
6
E
4
5
C
RPF tree from E RPF tree from C RPF tree from A
These trees have two interesting properties:
• They guarantee the fastest possible delivery, as multicasting follows the
shortest path from source to destination
• Better network utilization, since the packets are spread over multiple
links.
Drawback
✘Group membership is not taken into account when building the tree
⇒ a network can receive two or more copies of a multicast packet
Maguire Reverse -Path Forwarding (RPF) 8: 39 of 78
maguire@kth.se 2010.03.21 Internetworking/Internetteknik