Adding a multicast stream using L3

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  • Updated 8 months ago
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I have added a new multicast stream , I have the server and on layer 2 I can see the correct streams ,, and on the edge device,  I have MOP configured on the vlan and on the interlink vlan on the routing points  , I have a rp configured and a cbsp both configured on our core .

There is a profile configured

The source address is

From the edge I get:   4  0  255  0 0  0   0  0     0      0

So we can see a number of streams from the address

From the edge switch

 Slot-1 K2-SVR-SW-DS-1.1 # sh pim rp-set
Group           Mask            C-RP            Origin    Priority  Timeout Bootstrap 75        119
Slot-1 K2-SVR-SW-DS-1.2 #

Which is understand is correct.

When looking at the core :

sh  igmp snooping vLAN xxx-CORE-RT_xxx-SVR-DS_VR-Default

Which is the point to point link between my core and edge switch

I can see

LAN xxx-CORE-RT_xxx-SVR-DS_VR-Default (xxx) Snooping=Enabled
    Group           Sender          Age 10 1   0  0  0  0 ( I understand this is a SAP/SNMP comms )

    6 Incoming multicast streams

    Port   Host            Subscribed        Age    Group-Limit
    1 All Groups        3      0

So my question is why cannot I see the stream on the core .

What is address from source ? (SAP/sNMP )

I can see the above but not the address :( is the address that I am looking for the stream from

 ( Stream address )

So what am I missing ?

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Rod Robertson

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Posted 8 months ago

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Bastian Sprotte, Employee

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Hello Rob,
please check the TTL from the stream, you just trace the packets with Wireshark,
this will allow to see is the TTL will allow to route the packet.
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Rod Robertson

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Hi Sorry for the delay , I go back out to site later this week so I can check.

Carrying on from this .

I know PIM uses the configured routing protocol , in this case OSPF.

The vlan that I have this server on is part of OSPF area though it is configure as Passive would this have an effect on the multicast .

Sort of funny question as the SAP Multicast is getting through.

Looking forward to any suggestions

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EtherMAN, Embassador

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Couple of comments ... First when i see the and 255 I am pretty certain then that is a windows box of some kind with Universal Plug and Play enabled.  It typically  uses port 1900 and can be very chatty.  

As far as the stream mcast address not showing up in the core not sure about that but as a rule it will only be learned when there is a valid client asking for the stream and the stream being forwarding across the core link and active.  
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Rod Robertson

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Well Its been a few weeks now .

Returned to site to do some more investigation.

It would appear that the multicast was working for the rest of the network , just not the distribution pair of switches I was connected to , and testing on ..

So basically that's it , thanslk for all your help , I expect in my environment it will be another 5 years till I look at this again