From: Bit Gossip (bit.gossip@chello.nl)
Date: Sun Mar 25 2007 - 07:54:48 ART
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
This archive was generated by hypermail 2.1.4 : Sun Apr 01 2007 - 06:35:52 ART