Information Technology Reference
In-Depth Information
Example 11-3
Multicast State Maintained After Pruning (Continued)
Outgoing interface flags: H - Hardware switched
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 224.1.1.1), 00:00:21/stopped, RP 0.0.0.0, flags: D
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0, Forward/Dense, 00:00:21/00:00:00
(10.5.1.5, 224.1.1.1), 00:00:21/00:02:42, flags: PT
Incoming interface: Serial2/0, RPF nbr 10.2.1.29
Outgoing interface list: Null
This flood-and-prune process repeats every 3 minutes for all multicast streams. When
Receiver 2 comes online, R6 sends a Graft message upstream to build the MDT. This is
possible because R6 maintains the (S,G) with the empty OIL from the flood-and-prune
process, as shown in Example 11-3. The graft behavior is shown in Figure 11-10.
Figure 11-10
New Receiver Grafting onto Source Tree
R3
R1
R2
R6
Receiver
Source
R5
Tr affic
Graft
R4
R7
Receiver
As shown in Example 11-4, the state on R6 is updated to forward traffic to Receiver 2 with
the addition of the Ethernet0/0 interface to the OIL and the removal of the P flag (Prune)
from the (S,G) entry.
