From: Edison Ortiz (edisonmortiz@gmail.com)
Date: Sun Mar 25 2007 - 11:12:59 ART
You need to enable pim nbma mode in R2's serial interface to avoid the
flooding from spoke to spoke.
----- Original Message -----
From: "Bit Gossip" <bit.gossip@chello.nl>
To: "ccielab" <ccielab@groupstudy.com>
Sent: Sunday, March 25, 2007 6:54 AM
Subject: multicast very fundamental
> Group I am stuck for days on this very fundamental multicast
> mechanics...
> I noticed this strange thing while playing with the multicast task of
> IEWB4-LAB02 and couldn't get to the bottom of it; then I gave up.
> Now I have reproduced it in a very simple scenario, and the pb is still
> there.
>
> r1
> |
> |
> r2 ----<
> |
> |
> r3
>
> *) Frame relay hub'n'spoke with r2=hub, only serial physical interfaces
> *) Full reachability via OSPF
> *) PIM-SM with r2=RP; multicast source=132.1.26.8 attached to r2 f1/0
> for group 228.28.28.28; receivers attached to r1 and r3
> *) it works fine, all receivers get the group
>
> And now the funny part !!
> *) there is no layer 2 connectivity between r1 and r3 as you can see
> below; but still r1 HEARS the prune from r3 and OVERRIDES it !!!!!!!!
> How is it possible ??????
>
> When r3 leaves the group this is the pim debug on r1:
>
> PIM(0): Received v2 Join/Prune on Serial0/0 from 132.1.0.3, not to us
> PIM(0): Prune-list: (*, 228.28.28.28) RP 150.1.2.2
> PIM(0): Set join delay timer to 1000 msec for (150.1.2.2/32,
> 228.28.28.28) on Serial0/0
> PIM(0): Building Periodic (*,G) Join / (S,G,RP-bit) Prune message for
> 228.28.28.28
> PIM(0): Insert (*,228.28.28.28) join in nbr 132.1.0.2's queue
> PIM(0): Building Join/Prune packet for nbr 132.1.0.2
>
>
>
> This one is a classical example mentioned in Cisco doc, where PIM-SM
> goes into trouble because one spoke cannot hear the prune from another
> one and then override it; but in my lab it doesn't seem to happen....
>
> Below this line config and show's
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> r1
>
> ip multicast-routing
> interface Loopback0
> ip address 150.1.1.1 255.255.255.0
> ip pim sparse-dense-mode
> ip igmp join-group 228.28.28.28
> !
> interface FastEthernet0/0
> ip address 132.1.17.1 255.255.255.0
> ip pim sparse-mode
> speed 100
> full-duplex
> !
> interface Serial0/0
> ip address 132.1.0.1 255.255.255.0
> ip pim sparse-mode
> encapsulation frame-relay
> ip ospf network point-to-multipoint
> no fair-queue
> clock rate 64000
> frame-relay map ip 132.1.0.2 102 broadcast
> no frame-relay inverse-arp
> !
> router ospf 1
> router-id 150.1.1.1
> log-adjacency-changes
> passive-interface default
> no passive-interface Serial0/0
> network 132.1.0.1 0.0.0.0 area 0
> network 132.1.17.1 0.0.0.0 area 0
> network 150.1.1.1 0.0.0.0 area 0
> !
> ip pim rp-address 150.1.2.2
> ip pim spt-threshold infinity
>
> --------
>
> r1#show frame-relay map
> Serial0/0 (up): ip 132.1.0.2 dlci 102(0x66,0x1860), static,
> broadcast,
> CISCO, status defined, active
> r1#ping 224.0.0.2
>
> Type escape sequence to abort.
> Sending 1, 100-byte ICMP Echos to 224.0.0.2, timeout is 2 seconds:
>
> Reply to request 0 from 132.1.17.7, 4 ms
> Reply to request 0 from 132.1.0.2, 88 ms
> Reply to request 0 from 150.1.1.1, 4 ms
>
> r1#show ip mroute 228.28.28.28
> IP Multicast Routing Table
>
> (*, 228.28.28.28), 00:49:48/00:02:58, RP 150.1.2.2, flags: SCL
> Incoming interface: Serial0/0, RPF nbr 132.1.0.2
> Outgoing interface list:
> Loopback0, Forward/Sparse-Dense, 00:47:47/00:02:39
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> r2
>
> ip multicast-routing
> !
> interface Loopback0
> ip address 150.1.2.2 255.255.255.0
> ip pim sparse-mode
> !
> interface FastEthernet1/0
> ip address 132.1.26.2 255.255.255.0
> ip pim sparse-mode
> no ip mroute-cache
> duplex full
> !
> interface Serial4/0
> ip address 132.1.0.2 255.255.255.0
> ip pim sparse-mode
> encapsulation frame-relay
> ip ospf network point-to-multipoint
> no ip mroute-cache
> serial restart-delay 0
> frame-relay lmi-type cisco
> !
> router ospf 1
> router-id 150.1.2.2
> log-adjacency-changes
> passive-interface default
> no passive-interface Serial4/0
> network 132.1.0.2 0.0.0.0 area 0
> network 132.1.26.2 0.0.0.0 area 0
> network 150.1.2.2 0.0.0.0 area 0
> !
> ip pim rp-address 150.1.2.2
>
> --------
>
> r2#show frame-relay map
> Serial4/0 (up): ip 132.1.0.1 dlci 201(0xC9,0x3090), dynamic,
> broadcast,
> CISCO, status defined, active
> Serial4/0 (up): ip 132.1.0.3 dlci 203(0xCB,0x30B0), dynamic,
> broadcast,, status defined, active
> r2#ping 224.0.0.2
>
> Type escape sequence to abort.
> Sending 1, 100-byte ICMP Echos to 224.0.0.2, timeout is 2 seconds:
>
> Reply to request 0 from 150.1.2.2, 1 ms
> Reply to request 0 from 132.1.0.1, 76 ms
> Reply to request 0 from 132.1.0.3, 64 ms
>
> r2#show ip mroute 228.28.28.28
> IP Multicast Routing Table
>
>
> (*, 228.28.28.28), 01:01:35/00:03:10, RP 150.1.2.2, flags: S
> Incoming interface: Null, RPF nbr 0.0.0.0
> Outgoing interface list:
> Serial4/0, Forward/Sparse, 00:50:51/00:03:10
>
> (132.1.26.8, 228.28.28.28), 00:01:18/00:03:22, flags: T
> Incoming interface: FastEthernet1/0, RPF nbr 0.0.0.0
> Outgoing interface list:
> Serial4/0, Forward/Sparse, 00:01:18/00:03:10
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> r3
>
> ip multicast-routing
> !
> interface Loopback0
> ip address 150.1.3.3 255.255.255.0
> !
> interface FastEthernet3/0
> ip address 132.1.33.3 255.255.255.0
> ip pim sparse-mode
> ip policy route-map T8.2
> duplex full
> !
> interface Serial4/0
> bandwidth 512
> ip address 132.1.0.3 255.255.255.0
> ip pim sparse-mode
> encapsulation frame-relay
> ip ospf network point-to-multipoint
> serial restart-delay 0
> frame-relay map ip 132.1.0.2 302 broadcast
> no frame-relay inverse-arp
> !
> router ospf 1
> router-id 150.1.3.3
> log-adjacency-changes
> passive-interface default
> no passive-interface Serial4/0
> network 132.1.0.3 0.0.0.0 area 0
> network 132.1.3.3 0.0.0.0 area 0
> network 132.1.33.3 0.0.0.0 area 0
> network 150.1.3.3 0.0.0.0 area 0
> !
> ip pim rp-address 150.1.2.2
> ip pim spt-threshold infinity
>
> -----------
>
> r3#show frame-relay map
> Serial4/0 (up): ip 132.1.0.2 dlci 302(0x12E,0x48E0), static,
> broadcast,
> CISCO, status defined, active
> r3#ping 224.0.0.2
>
> Type escape sequence to abort.
> Sending 1, 100-byte ICMP Echos to 224.0.0.2, timeout is 2 seconds:
>
> Reply to request 0 from 132.1.0.2, 116 ms
>
> r3#show ip mroute 228.28.28.28
> IP Multicast Routing Table
>
> (*, 228.28.28.28), 00:02:13/00:02:59, RP 150.1.2.2, flags: SCL
> Incoming interface: Serial4/0, RPF nbr 132.1.0.2
> Outgoing interface list:
> FastEthernet3/0, Forward/Sparse, 00:02:13/00:02:33
>
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