114
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 messages
of the BSR do not contain the information of that C-RP.
•
In addition, if the BSR does not have a unicast route to a C-RP, it discards the C-RP-Adv messages
from that C-RP. Therefore, the bootstrap messages of the BSR do not contain the information of that
C-RP.
•
The RP is the core of a PIM-SM domain. Make sure 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
1.
Use the
display ip routing-table
command to verify that routes to the RP and the BSR are available
on each router and that a route between the RP and the BSR is available. Make sure 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.
2.
PIM-SM needs the support of the RP and BSR. Use the
display pim bsr-info
command to verify that
the BSR information exists on each router, and then use the
display pim rp-info
command to verify
that the RP information is correct on each router.
3.
Use the
display pim neighbor
command to verify that the normal PIM neighboring relationship has
been established among the routers.
