Help with multicast setup

[perpaal]

Hi, I`m attempting to set up a multicast in ouer network.

The multicast is provided by a IPTV provider.

Uplink from service provider is located at site A.

My RP is set up at site B.

From site A to B I have set up a VLAN (VLAN 400) to link the IPTV provider uplink to my RP.

The IPTV providers uplink is located at port 3 on site A.

On site B I have defined a VLAN (800) where I want to connect the multicast clients.

In VLAN 800 I connect a PC trying to connect to one of the multicast services with VLC (from instructions from IPTV provider), but it does not work.

This is my first multicast setup, so I probably have some mistakes in my config.

Need some good tips fast here

This is my current config:

Site A: Cisco 3750

ip vrf multicast

rd 1:2

!

ip vrf Management

rd 1:1

!

ip multicast-routing vrf multicast distributed

!

vlan 500

name Management

!

vlan 400

name Linknet_IPTV

!

interface GigabitEthernet1/0/1

description Link_site_B

switchport trunk encapsulation dot1q

switchport mode trunk

!

interface GigabitEthernet1/0/3

description Link_to IPTV_provider

switchport access vlan 400

switchport mode access

!

interface Vlan500

ip vrf forwarding Management

ip address 10.1.0.2 255.255.255.0

!

interface Vlan400

ip vrf forwarding multicast

no ip address

ip pim sparse-mode

Site B: Cisco 3750

system mtu routing 1500

vtp mode transparent

ip routing

!

ip vrf multicast

rd 1:2

!

ip vrf Management

rd 1:1

!

ip multicast-routing vrf multicast distributed

!

spanning-tree mode pvst

spanning-tree extend system-id

!

vlan internal allocation policy ascending

!

vlan 500

name Management

!

vlan 400

name Linknet_IPTV

!

vlan 800

name Multicast

!

interface Loopback1

description RP-Local

ip vrf forwarding multicast

ip address 10.150.0.134 255.255.255.255

ip pim sparse-mode

!

interface GigabitEthernet2/0/1

description Link_site_A

switchport trunk encapsulation dot1q

switchport mode trunk

!

interface Vlan500

ip vrf forwarding Management

ip address 10.1.0.1 255.255.255.0

!

interface Vlan400

ip vrf forwarding multicast

ip address 10.250.250.2 255.255.255.252

ip pim sparse-mode

!

interface Vlan800

ip vrf forwarding multicast

ip address 10.160.0.1 255.255.255.0

ip pim sparse-mode

!

ip route vrf multicast 0.0.0.0 10.250.250.1

!

ip pim vrf multicast rp-address 10.150.0.134

ip msdp vrf multicast peer 10.10.0.15 connect-source Loopback1

ip msdp vrf multicast description 10.10.0.15 ##Multicast##

ip msdp vrf multicast cache-sa-state

ip msdp vrf multicast rpf rfc3618

[Vaibhava Varma]

Hi perpaal

Can you confirm your current deployment setup..will be good if you can share a network topology diagram..From reading above I understand this

Users------Vlan800--SiteB-----Vlan400(PIM)----SiteA (L2)---Vlan400(PIM)---ISP (IPTV Provider)

SiteA is just L2 for your setup.So the issue lies at SiteB. Has the ISP agreed to do MSDP peering with you. Does the ISP has reverse route for VLAN800 and Lo1.

Can you share below outputs

sh ip pim neighbour

sh ip pim rp mapping

sh ip mroute

sh ip msdp peer

sh ip msdp sa

Regards

Varma

[perpaal]

Thank you for quick reply.

Site A is just L2 that is correct.

IPTV service provider har agreed to MSDP peering.

The ISP has reverse routes to my network.

sh ip pim vrf multicast neighbour = Empty table

sh ip pim vrf multicast rp = Empty table

sh ip mroute vrf multicast=

(*, 224.0.1.40), 01:34:39/00:02:55, RP 0.0.0.0, flags: DCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Loopback0, Forward/Sparse, 01:34:38/00:02:55

sh ip msdp vrf multicast peer=

MSDP Peer 10.10.0.15 (?), AS ?

Description: #Provider RP#

Connection status:

State: Up, Resets: 0, Connection source: Loopback0 (141.0.224.134)

Uptime(Downtime): 01:19:31, Messages sent/received: 79/859

Output messages discarded: 0

Connection and counters cleared 01:34:21 ago

SA Filtering:

Input (S,G) filter: none, route-map: none

Input RP filter: none, route-map: none

Output (S,G) filter: none, route-map: none

Output RP filter: none, route-map: none

SA-Requests:

Input filter: none

Peer ttl threshold: 0

SAs learned from this peer: 392

Number of connection transitions to Established state: 1

Input queue size: 0, Output queue size: 0

sh ip msdp vrf multicast sa=

MSDP Source-Active Cache - 393 entries

And a list of these entries ....

[Edison Ortiz]

Before we start troubleshooting multicast, let's examine your unicast routing.

Does the IPTV provider knows about subnet 10.160.0.0/24?

I see the switch has a default route towards 10.250.250.1 but they need to have a subnet route back to 10.160.0.0/24.

Can you ping the IPTV source from your PC running VLC?

Also, if you are running VLC - I believe you have to modify the TTL which defaults to 1. I personally have never used VLC for multicast testing because it tends to be buggy.

If you were using a multicast client, we should be able to see a *,G for the intended group in your local RP. Your mroute table is empty.

Regards,

Edison

[perpaal]

Yes the provider has the 10.160.0.0 net in its routes.

I can ping the providers RP (MSDP peer) from the PC.

But I do not get any PIM  neighbour, should there be anything here?

What might be the reason that I do not get this, is there somethins missing in my config, or is it at the providers side?

[Edison Ortiz · Accepted solution]

Your neighbor information will be under vrf multicast, thus the command is show ip pim vrf multicast neighbor

Do you see it now?

If not, then the provider does not have PIM enabled on their L3 interface that is connected to your L2 switch (interface

10.250.250.1/30)

[Vaibhava Varma]

Hi perpaal

PIM neighbourship would be required between the Site B and ISP for completing the mutlicast traffic path in Inter-AS Multicast Scenario when using MSDP. ( Though I have seen the first mcast flow to work in Inter-AS even wothout PIM but later traffic drops) so we wll need PIM to be enabled by the ISP on their downlink interface to SiteA as one important condition for multicast traffic to flow is that uRPF neighbour should be same as PIM neighbour for multicast traffic to flow which is not happening here.

Also very important point is to disable the flow of multicast packets between Site B and ISP in this scenario so that no unwanted updates cross between SiteB and ISP. We would need to block 224.0.1.39 and 224.0.1.40 between the Site B and ISP using ACL and permit rest.

A sample config would be:

int vlan400

ip pim sparse-mode

ip multicast boundary 1

!

access-list 1 deny 224.0.1.39

access-list 1 deny 224.0.1.40

access-list 1 permit any

!

Please have the ISP enable PIM on their downlink interface and configure the multicast boundary as above ( also remind ISP for multicast boundary or bsr-border if using BSR) and we should be good to go as the MSDP is up and its caching the multicast states fine. Also the uRPF should be fine now since we have only single routing path between SiteB and ISP and we have all the required routing in place.

Hope this helps to resolve your issue. Do let know for any clarifications and how we move ahead on this issue,

Regards

Varma

[perpaal]

Thank you for great help.

The problem was at the service providers side, even though they assured me that they had all set up

They had not set pim sparse-mode at the interface.

Now it works like a charm.

[Vaibhava Varma]

Hiperpaal

Glad to hear its working now.

Regards

Varma