RE: multicast first ping puzzel!!

From: Huan Pham (Huan.Pham@peopletelecom.com.au)
Date: Wed Oct 01 2008 - 03:44:04 ART


Hi Adam,

I am curious to find out the cause of the problems you posted, but I
have to tell you, the way you presented your problem is too broad.
It could be anything, e.g. related to routing (OSPF network type?), RP
advertisment, RPF failure, PIM MBMA mode.

Anyway, my guess is that, your first successful ping maybe due to the
mutlicast works in a Dense mode for that group, when the RP info is not
yet propagated. After that RP is advertized, and the multicast for that
group works in Sparse mode, and for some reason, your sparse mode is
broken somewhere.

It would be better if you post your config, that would help us to narrow
down the problem, and maybe we could find out the problem other than
blaming it to an IOS bug.

I tried on my pod (using OSPF network type point to multipoint, AutoRP)
and it works just fine. I do not see any issue. I do not have to set up
any tunnel between two spokes. My IOS and config are below. You can try
it out on your pod, and let me know if you see any problems. Also, pls
post your config, so I can test on my one.

R1#sh ver | in IOS
Cisco IOS Software, C2600 Software (C2600-ADVENTERPRISEK9-M), Version
12.4(13b), RELEASE SOFTWARE (fc3)

R2#sh ver | in IOS
Cisco IOS Software, C2600 Software (C2600-ADVENTERPRISEK9-M), Version
12.4(13b), RELEASE SOFTWARE (fc3)

R3#sh ver | in IOS
Cisco IOS Software, 3600 Software (C3640-JK9O3S-M), Version 12.4(5a),
RELEASE SOFTWARE (fc3)

R1#
ip multicast-routing

interface Serial0/0
 ip address 123.0.0.1 255.255.255.0
 ip pim sparse-dense-mode
 encapsulation frame-relay
 ip ospf network point-to-multipoint
 frame-relay map ip 123.0.0.2 102 broadcast
 no frame-relay inverse-arp
!
!
router ospf 1
 network 123.0.0.1 0.0.0.0 area 0

R2#

ip multicast-routing

interface Loopback0
 ip address 2.2.2.2 255.255.255.255
 ip pim sparse-dense-mode

interface Serial0/0
 ip address 123.0.0.2 255.255.255.0
 ip pim nbma-mode
 ip pim sparse-dense-mode
 encapsulation frame-relay
 ip ospf network point-to-multipoint
 frame-relay map ip 123.0.0.1 201 broadcast
 frame-relay map ip 123.0.0.3 203 broadcast
 no frame-relay inverse-arp
!
!
router ospf 1
 network 2.2.2.2 0.0.0.0 area 0
 network 123.0.0.2 0.0.0.0 area 0
!
!
ip pim send-rp-announce Loopback0 scope 16 interval 10
ip pim send-rp-discovery Loopback0 scope 16 interval 10

R3#

ip multicast-routing
!
!
!
!
interface Serial2/0
 ip address 123.0.0.3 255.255.255.0
 ip pim sparse-dense-mode
 encapsulation frame-relay
 ip ospf network point-to-multipoint
 ip igmp join-group 224.3.3.3
 frame-relay map ip 123.0.0.2 302 broadcast
 no frame-relay inverse-arp
!
!
router ospf 1
 network 123.0.0.3 0.0.0.0 area 0

R1#ping 224.3.3.3 rep 5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 224.3.3.3, timeout is 2 seconds:

Reply to request 0 from 123.0.0.3, 156 ms
Reply to request 1 from 123.0.0.3, 116 ms
Reply to request 2 from 123.0.0.3, 116 ms
Reply to request 3 from 123.0.0.3, 116 ms
Reply to request 4 from 123.0.0.3, 116 ms

R1#sh ip pim rp mapping
PIM Group-to-RP Mappings

Group(s) 224.0.0.0/4
  RP 2.2.2.2 (?), v2v1
    Info source: 2.2.2.2 (?), elected via Auto-RP
         Uptime: 00:14:50, expires: 00:00:29

R2#sh ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)

Group(s) 224.0.0.0/4
  RP 2.2.2.2 (?), v2v1
    Info source: 2.2.2.2 (?), elected via Auto-RP
         Uptime: 00:16:14, expires: 00:00:26
R2#sh ip mroute
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,
       Z - Multicast Tunnel, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 224.3.3.3), 00:15:50/00:03:27, RP 2.2.2.2, flags: SJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Serial0/0, 123.0.0.3, Forward/Sparse-Dense, 00:12:52/00:03:27

(123.0.0.1, 224.3.3.3), 00:01:54/00:01:16, flags: JT
  Incoming interface: Serial0/0, RPF nbr 123.0.0.1
  Outgoing interface list:
    Serial0/0, 123.0.0.3, Forward/Sparse-Dense, 00:01:54/00:03:27

(*, 224.0.1.39), 00:16:41/stopped, RP 0.0.0.0, flags: DCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Loopback0, Forward/Sparse-Dense, 00:16:23/00:00:00
    Serial0/0, Forward/Sparse-Dense, 00:16:41/00:00:00

(2.2.2.2, 224.0.1.39), 00:16:41/00:03:29, flags: LT
  Incoming interface: Loopback0, RPF nbr 0.0.0.0
  Outgoing interface list:
    Serial0/0, Prune/Sparse-Dense, 00:10:31/00:02:28

(*, 224.0.1.40), 00:19:26/stopped, RP 0.0.0.0, flags: DCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Loopback0, Forward/Sparse-Dense, 00:16:25/00:00:00
    Serial0/0, Forward/Sparse-Dense, 00:19:26/00:00:00

(2.2.2.2, 224.0.1.40), 00:16:22/00:02:57, flags: LT
  Incoming interface: Loopback0, RPF nbr 0.0.0.0
  Outgoing interface list:
    Serial0/0, Forward/Sparse-Dense, 00:16:22/00:00:00

R2#sh ip mroute count
IP Multicast Statistics
6 routes using 3596 bytes of memory
3 groups, 1.00 average sources per group
Forwarding Counts: Pkt Count/Pkts(neg(-) = Drops) per second/Avg Pkt
Size/Kilobits per second
Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc)

Group: 224.3.3.3, Source count: 1, Packets forwarded: 5, Packets
received: 5
  RP-tree: Forwarding: 0/0/0/0, Other: 0/0/0
  Source: 123.0.0.1/32, Forwarding: 5/0/100/0, Other: 5/0/0

Group: 224.0.1.39, Source count: 1, Packets forwarded: 0, Packets
received: 0
  Source: 2.2.2.2/32, Forwarding: 0/0/0/0, Other: 0/0/0

Group: 224.0.1.40, Source count: 1, Packets forwarded: 0, Packets
received: 0
  Source: 2.2.2.2/32, Forwarding: 0/0/0/0, Other: 0/0/0

R3#sh ip pim rp mapping
PIM Group-to-RP Mappings

Group(s) 224.0.0.0/4
  RP 2.2.2.2 (?), v2v1
    Info source: 2.2.2.2 (?), elected via Auto-RP
         Uptime: 00:18:32, expires: 00:00:27
R3#sh ip mroute
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,
       Z - Multicast Tunnel, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 224.3.3.3), 00:18:08/stopped, RP 2.2.2.2, flags: SJPCLF
  Incoming interface: Serial2/0, RPF nbr 123.0.0.2
  Outgoing interface list: Null

(123.0.0.1, 224.3.3.3), 00:00:16/00:02:59, flags: PLFT
  Incoming interface: Serial2/0, RPF nbr 123.0.0.2
  Outgoing interface list: Null

(*, 224.0.1.39), 00:18:57/stopped, RP 0.0.0.0, flags: DC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Serial2/0, Forward/Sparse-Dense, 00:18:58/00:00:00

(2.2.2.2, 224.0.1.39), 00:00:37/00:02:22, flags: PTX
  Incoming interface: Serial2/0, RPF nbr 123.0.0.2
  Outgoing interface list: Null

(*, 224.0.1.40), 00:21:23/stopped, RP 0.0.0.0, flags: DCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Serial2/0, Forward/Sparse-Dense, 00:21:24/00:00:00

(2.2.2.2, 224.0.1.40), 00:18:40/00:02:59, flags: PLTX
  Incoming interface: Serial2/0, RPF nbr 123.0.0.2
  Outgoing interface list: Null

R3#sh ip mroute count
IP Multicast Statistics
6 routes using 2608 bytes of memory
3 groups, 1.00 average sources per group
Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per
second
Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc)

Group: 224.3.3.3, Source count: 1, Packets forwarded: 0, Packets
received: 5
  RP-tree: Forwarding: 0/0/0/0, Other: 0/0/0
  Source: 123.0.0.1/32, Forwarding: 0/-1/0/0, Other: 5/0/5

Group: 224.0.1.39, Source count: 1, Packets forwarded: 0, Packets
received: 5
  Source: 2.2.2.2/32, Forwarding: 0/-1/0/0, Other: 5/0/5

Group: 224.0.1.40, Source count: 1, Packets forwarded: 0, Packets
received: 113
  Source: 2.2.2.2/32, Forwarding: 0/-1/0/0, Other: 113/0/113

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Adam Elghafri
Sent: Monday, 29 September 2008 8:39 PM
To: Biddu Mehta
Cc: Jonny English; Julian Pentermann; Cisco certification
Subject: Re: multicast first ping puzzel!!

... i really hope its an IOS issue....

On Mon, Sep 29, 2008 at 3:46 PM, Biddu Mehta <biddumehta@gmail.com>
wrote:

> I do not remember the exact IOS .
>
> But the observations were seen on different IOS .
>
> Also i thing you can check is changing the dr-priority , and make the
> dr-priority high towards RP . I am not sure , if this will help for
> ping issue.
>

--
Adam - Dubai

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