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Multicast dropped. Why?

Hello!

 

I have very simple multicast network (scheme attached).

The problem is that router R1 (Catalyst 3750 both) is dropping multicast traffic on upstream interface.

 

Debug message is:

1d19h: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=6006, ttl=28, prot=17, len=1358(1344), not RPF interface
1d19h: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=6007, ttl=28, prot=17, len=1358(1344), not RPF interface
1d19h: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=6008, ttl=28, prot=17, len=1358(1344), not RPF interface
1d19h: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=6009, ttl=28, prot=17, len=1358(1344), not RPF interface
1d19h: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=6010, ttl=28, prot=17, len=1358(1344), not RPF interface
1d19h: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=6011, ttl=28, prot=17, len=1358(1344), not RPF interface
1d19h: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=6012, ttl=28, prot=17, len=1358(1344), not RPF interface
1d19h: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=6013, ttl=28, prot=17, len=1358(1344), not RPF interface

 

RPF check is Ok for the source 10.242.1.2:

R1#sh ip rpf 10.242.1.2
RPF information for ? (10.242.1.2)
RPF interface: Vlan2018
RPF neighbor: ? (10.242.128.49)
RPF route/mask: 10.242.1.2/32
RPF type: unicast (static)
RPF recursion count: 0
Doing distance-preferred lookups across tables

 

 

What does it mean? And how to fix it?

 

Here ar configs:

 

 

R1 config:


ip multicast-routing distributed
!
!
vlan 2018
name MCast_SOURCES
!
!
interface Loopback0
ip address 10.1.1.2 255.255.255.255
!
interface FastEthernet1/0/1
switchport access vlan 2018
switchport trunk encapsulation dot1q
switchport mode access
spanning-tree portfast
!
interface FastEthernet1/0/2
no switchport
ip address 192.168.12.73 255.255.255.252
ip pim sparse-mode
!
!
interface Vlan2018
ip address 10.242.128.50 255.255.255.240
ip pim passive
load-interval 30
!
router ospf 100
log-adjacency-changes
redistribute static subnets
passive-interface default
no passive-interface FastEthernet1/0/2
network 10.0.0.0 0.255.255.255 area 0
network 192.168.12.0 0.0.0.255 area 0
!
ip classless
ip route 10.242.1.2 255.255.255.255 10.242.128.49
!
ip pim rp-address 10.1.1.10 override

 

R2 config:

!
!
ip multicast-routing distributed
!
!
interface Loopback0
ip address 10.1.1.10 255.255.255.255
ip pim sparse-mode
!
interface FastEthernet1/0/1
no switchport
ip address 192.168.12.74 255.255.255.252
ip pim sparse-mode
!
interface FastEthernet1/0/2
switchport access vlan 14
switchport mode access
load-interval 30
spanning-tree portfast
!
!
interface Vlan14
ip address 192.168.14.1 255.255.255.0
ip pim sparse-mode
ip igmp static-group 233.32.210.77
!
router ospf 100
log-adjacency-changes
passive-interface default
no passive-interface FastEthernet1/0/1
network 10.0.0.0 0.255.255.255 area 0
network 192.168.12.0 0.0.0.255 area 0
!
!
ip pim rp-address 10.1.1.10 override
!

1 Accepted Solution

Accepted Solutions

For interdomain multicast routing MSDP must be configured at least.

Or source address of multicast group must be directly connected on the FHR.

View solution in original post

7 Replies 7

mroute on R1:
R1#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

(*, 233.32.210.251), 00:00:02/00:02:57, RP 10.1.1.10, flags: SP
Incoming interface: FastEthernet1/0/2, RPF nbr 192.168.12.74
Outgoing interface list: Null

(*, 224.0.1.40), 00:00:02/00:02:57, RP 10.1.1.10, flags: SJCL
Incoming interface: FastEthernet1/0/2, RPF nbr 192.168.12.74
Outgoing interface list:
Loopback0, Forward/Sparse, 00:00:03/00:02:56

Mroute on R2:
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

(*, 233.32.210.251), 00:16:14/stopped, RP 10.1.1.10, flags: SJC
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Vlan14, Forward/Sparse, 00:16:14/00:01:54

(*, 224.0.1.40), 00:16:14/00:02:58, RP 10.1.1.10, flags: SJCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
FastEthernet1/0/1, Forward/Sparse, 00:15:33/00:03:16
Loopback0, Forward/Sparse, 00:16:14/00:02:58

But incoming traffic is dropped on R1/

Hello

Pim is missing on the SVI, try applying it.

interface Vlan2018
ip address 10.242.128.50 255.255.255.240
ip pim passive
ip pim sparse-mode <----

also show ip route and traceroute to 10.242.1.2 is this going the correct path as MC is expecting it to.


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

Hi Paul

 

I've changed config, result is the same:

00:09:52: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=55823, ttl=28, prot=17, len=1358(1344), not RPF interface
00:09:52: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=55824, ttl=28, prot=17, len=1358(1344), not RPF interface
00:09:52: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=55825, ttl=28, prot=17, len=1358(1344), not RPF interface
00:09:52: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=55826, ttl=28, prot=17, len=1358(1344), not RPF interface
00:09:52: IP(0): s=10.242.1.2 (Vlan2018) d=233.32.210.77 id=55827, ttl=28, prot=17, len=1358(1344), not RPF interface

 

 

R1#sh ip pim int         

Address          Interface                Ver/   Nbr    Query  DR     DR
                                          Mode   Count  Intvl  Prior
10.1.1.2         Loopback0                v2/S   0      30     1      10.1.1.2
192.168.12.73    FastEthernet1/0/2        v2/S   1      30     1      192.168.12.74
192.168.15.1     FastEthernet1/0/3        v2/S   0      30     1      0.0.0.0
10.242.128.50    Vlan2018                 v2/S   1      30     1      10.242.128.50

 

 

R1#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

(*, 233.32.210.77), 00:13:59/00:02:58, RP 10.1.1.10, flags: SP
Incoming interface: FastEthernet1/0/2, RPF nbr 192.168.12.74
Outgoing interface list: Null

(*, 224.0.1.40), 00:14:06/00:02:32, RP 10.1.1.10, flags: SJCL
Incoming interface: FastEthernet1/0/2, RPF nbr 192.168.12.74
Outgoing interface list:
Loopback0, Forward/Sparse, 00:14:04/00:02:32



R1#sh run int vlan 2018
Building configuration...

Current configuration : 106 bytes
!
interface Vlan2018
ip address 10.242.128.50 255.255.255.240
ip pim sparse-mode
load-interval 30
end



R1#sh ip route 10.242.1.2
Routing entry for 10.242.1.2/32
Known via "static", distance 1, metric 0
Redistributing via ospf 100
Advertised by ospf 100 subnets
Routing Descriptor Blocks:
* 10.242.128.49
Route metric is 0, traffic share count is 1



R1#sh ip route 10.242.128.49
Routing entry for 10.242.128.48/28
Known via "connected", distance 0, metric 0 (connected, via interface)
Routing Descriptor Blocks:
* directly connected, via Vlan2018
Route metric is 0, traffic share count is 1



R1#trace 10.242.1.2

Type escape sequence to abort.
Tracing the route to 10.242.1.2

1 10.242.128.49 0 msec 8 msec 0 msec
2 * * * 
3 * * * 
4 * *

 

10.242.1.2 and 10.242.128.49 are in provider network and dont reply to ping.

Provider send me static multicast group 233.32.210.77.

I'm really confused what is wrong.

 

P.S. PIM passive mode means that the device will not send PIM messages on the interface nor will it accept PIM messages from other devices across this interface. The device will instead consider that it is the only PIM device on the network and thus act as the DR and also as the DF for all bidir-PIM group ranges. Isnt it?

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipmulti_pim/configuration/15-s/imc-pim-15-s-book/imc_stub_routing.html

Hello,

 

on R2 try and enter the below static mroute:

 

ip mroute 10.242.1.2 255.255.255.255 192.168.12.73

 

Where is the multicast source 10.242.1.2 ? It is not part of Vlan 2018 (the 10.242.128.48/28) network...

 

 

HI Georg

 

I've tried it. It does not help.

 

R2#sh ip rpf 10.242.1.2
RPF information for ? (10.242.1.2)
  RPF interface: FastEthernet1/0/1
  RPF neighbor: ? (192.168.12.73)
  RPF route/mask: 10.242.1.2/32
  RPF type: unicast (ospf 100)
  RPF recursion count: 0
  Doing distance-preferred lookups across tables
R2#
R2#
R2#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R2(config)#ip mroute 10.242.1.2 255.255.255.255 192.168.12.73
R2(config)#^Z
R2#sh ip rpf 10.242.1.2
RPF information for ? (10.242.1.2)
  RPF interface: FastEthernet1/0/1
  RPF neighbor: ? (192.168.12.73)
  RPF route/mask: 10.242.1.2/32
  RPF type: static
  RPF recursion count: 0
  Doing distance-preferred lookups across tables
R2#
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

(*, 239.255.255.250), 00:07:28/00:02:55, RP 10.1.1.10, flags: SJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Vlan14, Forward/Sparse, 00:03:33/00:02:55

(*, 233.32.210.77), 1d09h/00:02:51, RP 10.1.1.10, flags: SJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Vlan14, Forward/Sparse, 00:03:33/00:02:51

(*, 224.0.1.40), 1d09h/00:02:49, RP 10.1.1.10, flags: SJCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet1/0/1, Forward/Sparse, 1d09h/00:02:47
    Loopback0, Forward/Sparse, 1d09h/00:01:56

The working option I've found is to assigne RP to R1 (Lo0: 10.1.1.2).

In this case multicast flows through my network.

But it is undesirable.

 

For interdomain multicast routing MSDP must be configured at least.

Or source address of multicast group must be directly connected on the FHR.

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