[j-nsp] Problem with shared-joins on next-generation mVPN (BGP based)

[Mohamed Raddahi]

Hi All,

I came across following issue with shared-joins while trying to figure out how 
next-generation mVPN in R9.3 works:

Setup:   PIM-receiver --- PE1(M10) ------  PE2(M5) --- RP

If I setup an (S,G) PIM receiver with S=RP, then I see 
the source-join bgp message being sent from PE1 to PE2. 
This is how the PIM and MVPN route look like in PE1:

7:1:1:100:32:10.20.1.2:32:224.8.8.8/240 (1 entry, 1 announced)
        *PIM    Preference: 105
                Next hop type: Multicast (IPv4), Next hop index: 262144
                Next-hop reference count: 6
                State: <Active Int>
                Local AS:   100
                Age: 12:13
                Task: PIM.mvpn1
                Announcement bits (2): 1-mvpn global task 2-BGP RT Background
                AS path: I
                Communities: target:10.20.1.8:4
                
mvpn1.inet.1: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
 
224.8.8.8.10.20.1.2/64 (1 entry, 1 announced)
        *MVPN   Preference: 70
                Next hop type: Multicast (IPv4), Next hop index: 262144
                Next-hop reference count: 6
                State: <Active Int>
                Local AS:   100
                Age: 12:13
                Task: mvpn global task
                Announcement bits (1): 0-KRT
                AS path: I
                 
                               
If I setup an (*,G) PIM receiver, the shared-join gets assigned 
the "no-advertise" community and no MVPN route is created at all:


6:1:1:100:32:10.20.1.2:32:224.7.7.7/240 (1 entry, 1 announced)
        *PIM    Preference: 105
                Next hop type: Multicast (IPv4), Next hop index: 262144
                Next-hop reference count: 6
                State: <Active Int>
                Local AS:   100
                Age: 4:13
                Task: PIM.mvpn1
                Announcement bits (1): 1-mvpn global task
                AS path: I
                Communities: no-advertise target:10.20.1.8:4
 


Any idea why with the same configuration, source-joins get through the MVPN 
while shared-joins are blocked at the ingress PE ? What is so special about the 
shared-joins in the mVPN context ? (besides the RP that needs to be configured correctly)
I have included below a trace of pim in PE1 at reception of the shared-join.

Thanks in advance.

JT.



Apr 25 09:32:08.331814 PIM fe-0/1/1.2 RECV 92.0.0.2 -> 224.0.0.13 V2 JoinPrune to 92.0.0.1 holdtime 210 groups 1 sum 0x83c5 len 34
Apr 25 09:32:08.331862 group 224.7.7.7 joins 1 prunes 0
Apr 25 09:32:08.331881   join list:
Apr 25 09:32:08.331910     source 10.20.1.2 flags sparse,rptree,wildcard
Apr 25 09:32:08.332031 task_job_create_background: create prio 5 job PIM Nbr JP
for task PIM.mvpn1
Apr 25 09:32:08.332102 background dispatch running job PIM Nbr JP for task PIM.mvpn1
  
Apr 25 09:32:08.332306 EVENT:DS_JOIN
sgnode: 224.7.7.7.0.0.0.0 Flags-sm:wc:rpt:
        DSM: All macros empty
        US-FSM: US State:NOT_JOINED
        RPF: us interface - Pseudo-MVPN nbr addr - 0.0.0.0
J/P Attr: Flags:sm:wc:rpt: If:fe-0/1/1.2(p) Nbr:92.0.0.2 O:REMOTE-NBR Ht:210 AS: 0
Apr 25 09:32:08.332551 Create PIM CMcast: (224.7.7.7.0.0.0.0) IIF - gr-0/3/0.32769
Apr 25 09:32:08.332717 CHANGE   6:1:1:100:32:10.20.1.2:32:224.7.7.7/240  PIM
  pref 105/0 metric  <Active Int>
Apr 25 09:32:08.332770 ADD      6:1:1:100:32:10.20.1.2:32:224.7.7.7/240  PIM
  pref 105/0 metric  <Active Int>
Apr 25 09:32:08.332799 rt_close: 1 route proto PIM.mvpn1
Apr 25 09:32:08.332799
DS-FSM: IF/NBR fe-0/1/1.2/92.0.0.2() State NoInfo (NI) to Join (J)
Apr 25 09:32:08.332885 task_timer_ucreate: created timer PIM.mvpn1_RxJoin  flags <>
Apr 25 09:32:08.332928 task_timer_uset: timer PIM.mvpn1_RxJoin <Touched> set to
offset 3:30 at 9:35:38
  
EVENT:DS_IMMEDIATE_OLIST_BECOMES_NON_NULL
sg state: 224.7.7.7.0.0.0.0 Flags-sm:wc:rpt:
        DSM: IMM_OLIST(*,g):NE
        US-FSM: US State:NOT_JOINED
        RPF: us interface - Pseudo-MVPN nbr addr - 0.0.0.0
US-FSM: US Event - JOIN_DESIRED_TRUE Current State - NOT_JOINED New State - JOINED
US-FSM: RPF nbr old/new null/Pseudo-MVPN[0.0.0.0]
US-FSM: SENDING TRIGGER JOIN
US-FSM: SENDING PERIODIC JOIN
FWD-FSM:OIF List: IIF - fe-0/1/1.2 (Added)
FWD-FSM:OIF List: IIF - fe-0/1/1.2 (Added)
Apr 25 09:32:08.333330 Create PIM CMcast: (224.7.7.7.0.0.0.0) IIF - gr-0/3/0.32769
Apr 25 09:32:08.333384 CHANGE   6:1:1:100:32:10.20.1.2:32:224.7.7.7/240  PIM
  pref 105/0 metric  <Active Int>
Apr 25 09:32:08.333411 rt_close: 1 route proto PIM.mvpn1
Apr 25 09:32:08.333411
FWD-FSM:OIF List: IIF - fe-0/1/1.2 (Added)
Apr 25 09:32:08.333536 Create PIM CMcast: (224.7.7.7.0.0.0.0) IIF - gr-0/3/0.32769
Apr 25 09:32:08.333580 task_job_delete: delete background job PIM Nbr JP for task PIM.mvpn1
Apr 25 09:32:08.333610 background dispatch completed job PIM Nbr JP for task PIM.mvpn1
Apr 25 09:32:08.333968 rt_flash_update_callback: flash PIM.mvpn1 (mvpn1.mvpn.0)
start
Apr 25 09:32:08.334001 rt_flash_update_callback: flash PIM.mvpn1 (mvpn1.mvpn.0)
done