ip dense mode, how and where to enable state refresh.

[sarahr202]

Hi everybody.

Let say we have a  network as shown below:

10.10.10.1      s1 ( pruned)

server----------R1----------------------------R2

                          |                                         | s0 ( pruned)

                          |                                         |

                          |                                         |

                          |------s0-(RPF)-R3---S1( pruned)

                                                          |

                                                          |

                                                       host1    (224.7.7.7)

We are running Ip PIM dense on all routers.  For efficiency, we want to use " state refresh" message.

How do we enable it and where it should be enabled in our network above?

thanks and have a great day

[Peter Paluch · Accepted solution]

Hello Sarah,

PIM-DM State Refresh messages should be originated on first-hop routers of multicast sources, i.e. on those routers to which multicast sources are connected. The origination of these State Refresh messages is configured on first hop router interfaces that face towards the source. Assuming the topology is as follows:

Source --- (f0/0) R2 (f0/1) --- (f0/1) R3 (f0/0) --- (f0/0) R4

the ip pim state-refresh origination-interval N shall be configured on R2's f0/0 interface. The placement of this command is somewhat counterintuitive but logical - basically, you are configuring the router to watch for sender's activity on a particular interface, and send the State Refresh messages out all (other) interfaces that have received a PIM Prune message.

If the network where the multicast source is connected has multiple routers, both of them have to be configured using the same origination interval N.

Best regards,

Peter

[sarahr202]

Thanks Peter.

I put off CCNP Tshoot until May.  Have a job interview in next two weeks. There are few things I have to know. One of then is  PIM .  Unfortunately, CCNP route does not cover PIM.

I find your concept very strong.   I am reading this book from one of my favorite author. But I find the book wrong.

For example the book says " Assert message" is only used on a LAN link. However, When I performed the lab,I noticed that " Assert message" on a serial link. I spent the whole day figuring out  what is this assert message doing on serial link. I finally did. If I had a good book by  someone who has solid concept like you,It would help me tremendously.

Now every time I read my book, I feel maybe the book is wrong again.

Would you please share the list of books that helped you  build your concept and attain CCIE?

I will really appreciate that.