From: Chris Broadway (midatlanticnet@gmail.com)
Date: Mon Sep 18 2006 - 11:13:38 ART
Group,
Here is a multicast issue I am having. I cannot figure out what is
causeing
this behavior and therefore cannot figure out how to fix it. Here is the
topology:
R5 (Frame hub and Multicast RP)
/ \
frame/ \frame
/ \
R1 R2---ETH----R3
R5 is the RP for group 224.1.1.1 and 224.2.2.2. I have R5 configure for
the
mapping agent also. PIM Sparse mode only is used on the appropriate
interfaces of all routers. I am using AutoRP on all routers. Lo0 on r1 is
configured with the igmp join command. I can ping 224.1.1.1 and 224.2.2.2
from all routers.
Now here is the issue:
When I ping 224.1.1.1 or 224.2.2.2 from r2, I see the (S,G) in the mroute
table of r5 as (1.1.125.2, 224.1.1.1) and the outbound interface as serial
0/2. When I ping 224.1.1.1 from r3, I see the (S,G) in the mroute table
of
r5 as (1.1.62.8, 224.1.1.1) and the outbound interface as serial 0/2.
But, even though I can ping from r2 or r3...i can never ping at the same
time. When I send 500 pings from r2 to 224.1.1.1 first, I see pings from
r3
with an outbound interface as null on r5. If I stop the pings from r2, I
will see the outbound interface for the pings from r3 change to serial
0/2.
If I start the pings from r2 back up, the outbound interface on r5 for
that
new ping will be null.
Why is this happening and how do I fix it?
Here is the rp mapping on R5:
R5#sh ip pim rp map
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent
Group(s) 224.1.1.1/32
RP 5.5.5.5 (?), v2v1
Info source: 5.5.5.5 (?), elected via Auto-RP
Uptime: 00:01:38, expires: 00:00:25
Group(s) 224.2.2.2/32
RP 5.5.5.5 (?), v2v1
Info source: 5.5.5.5 (?), elected via Auto-RP
Uptime: 00:01:56, expires: 00:00:29
Here is the "sh ip mroute" on R5, before I start 100 pings from r2 and r3:
R5#sh ip mrout
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report
Outgoing interface flags: H - Hardware switched
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 224.0.1.39), 00:03:51/00:00:00, RP 0.0.0.0, flags: DCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0.5, Forward/Sparse, 00:02:54/00:00:00
Loopback0, Forward/Sparse, 00:03:51/00:00:00
(5.5.5.5, 224.0.1.39), 00:02:55/00:03:29, flags: CLT
Incoming interface: Loopback0, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0.5, Forward/Sparse, 00:02:54/00:00:00
(*, 224.0.1.40), 00:03:51/00:00:00, RP 0.0.0.0, flags: DCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0.5, Forward/Sparse, 00:02:40/00:00:00
Loopback0, Forward/Sparse, 00:03:52/00:00:00
(*, 224.1.1.1), 00:00:37/00:02:52, RP 5.5.5.5, flags: S
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0.5, 1.1.125.1, Forward/Sparse, 00:00:37/00:02:52
(*, 224.2.2.2), 00:00:36/00:02:53, RP 5.5.5.5, flags: S
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0.5, 1.1.125.1, Forward/Sparse, 00:00:36/00:02:53
Here is the mroute table for 224.1.1.1 on R5 after r2 and r3 have started
100 pings:
R5#sh ip mrout 224.1.1.1
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report
Outgoing interface flags: H - Hardware switched
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 224.1.1.1), 00:07:55/00:02:59, RP 5.5.5.5, flags: S
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0.5, 1.1.125.1, Forward/Sparse, 00:07:55/00:02:32
(1.1.28.2, 224.1.1.1), 00:00:30/00:02:29, flags:
Incoming interface: Serial2/0.5, RPF nbr 1.1.125.2
Outgoing interface list:
Serial2/0.5, 1.1.125.1, Forward/Sparse, 00:00:30/00:02:29
(1.1.28.8, 224.1.1.1), 00:00:27/00:02:54, flags: T
Incoming interface: Serial2/0.5, RPF nbr 1.1.125.2
Outgoing interface list:
Serial2/0.5, 1.1.125.1, Forward/Sparse, 00:00:27/00:02:32
(1.1.125.2, 224.1.1.1), 00:00:31/00:02:28, flags: T
Incoming interface: Serial2/0.5, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0.5, 1.1.125.1, Forward/Sparse, 00:00:31/00:02:28
Here is the mroute table for 224.1.1.1 on R5 after a minute or so into the
pings:
R5#sh ip mrout 224.1.1.1
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report
Outgoing interface flags: H - Hardware switched
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 224.1.1.1), 00:11:59/00:03:26, RP 5.5.5.5, flags: S
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Serial2/0.5, 1.1.125.1, Forward/Sparse, 00:11:59/00:03:26
(1.1.28.2, 224.1.1.1), 00:04:34/00:01:38, flags: P
Incoming interface: Serial2/0.5, RPF nbr 1.1.125.2
Outgoing interface list: Null
(1.1.28.8, 224.1.1.1), 00:04:31/00:01:41, flags: PT
Incoming interface: Serial2/0.5, RPF nbr 1.1.125.2
Outgoing interface list: Null
(1.1.125.2, 224.1.1.1), 00:04:35/00:02:59, flags: PT
Incoming interface: Serial2/0.5, RPF nbr 0.0.0.0
Outgoing interface list: Null
Why did the Outgoing interfaces go to NULL???
-Broadway
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