Rps Unable To Join Spt In Pim-Sm; Rpt Establishment Failure Or Source Registration Failure In Pim-Sm - HP A5500 SI Switch Series Configuration Manual

RPs unable to join SPT in PIM-SM

Symptom
An RPT cannot be established correctly, or the RPs cannot join the SPT to the multicast source.
Analysis
As the core of a PIM-SM domain, the RPs serve specific multicast groups. Multiple RPs can coexist
•
in a network. Make sure that the RP information on all routers is exactly the same and that a
specific group is mapped to the same RP. Otherwise, multicast forwarding will fail.
If the static RP mechanism is used, the same static RP command must be executed on all the routers
•
in the entire network. Otherwise, multicast forwarding will fail.
Solution
Verify that a route is available to the RP. Use the display ip routing-table command to determine
1.
whether a route is available on each router to the RP.
Verify the dynamic RP information. Use the display pim rp-info command to determine whether the
2.
RP information is consistent on all routers.
Verify the configuration of static RPs. Use the display pim rp-info command to determine whether
3.
the same static RP address has been configured on all the routers in the entire network.
RPT establishment failure or source registration failure in PIM-
SM
Symptom
C-RPs cannot unicast advertise messages to the BSR. The BSR does not advertise bootstrap messages
containing C-RP information and has no unicast route to any C-RP. An RPT cannot be established
correctly, or the DR cannot perform source registration with the RP.
Analysis
The C-RPs periodically send C-RP-Adv messages to the BSR by unicast. If a C-RP has no unicast
•
route to the BSR, the BSR cannot receive C-RP-Adv messages from that C-RP and the bootstrap
message of the BSR will not contain information about that C-RP.
If the BSR does not have a unicast route to a C-RP, it will discard the C-RP-Adv messages from that
•
C-RP. Therefore, the bootstrap messages of the BSR will not contain information about that C-RP.
The RP is the core of a PIM-SM domain. Be sure that the RP information on all routers is exactly the
•
same, a specific group G is mapped to the same RP, and unicast routes are available to the RP.
Solution
Verify that the routes to C-RPs and the BSR are available. Use the display ip routing-table command
1.
to determine whether the routes are available on each router to the RP and the BSR and whether a
route is available between the RP and the BSR. Be sure that each C-RP has a unicast route to the
BSR, the BSR has a unicast route to each C-RP, and all the routers in the entire network have a
unicast route to the RP.
Verify the RP and BSR information. PIM-SM needs the support of the RP and BSR. Use the display
2.
pim bsr-info command to determine whether the BSR information is available on each router, and
then use the display pim rp-info command to determine whether the RP information is correct.
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