PIM multicast and RP topology – need advice

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I have PIM SM running on a dual core 8810 environment with edge user switches connected.  The multicast source server used to terminate here but changed to a vm a few years back which moved to our TOR 10G switches, and these dc670’s connect directly to the Cores.  PIM still works even though the source server moved off the core.  The VLANs on the TOR switches are layer 2 only and I want to change these to layer 3 and enable forwarding.  I need advice because I’m unsure if I should enable IPMC forwarding as well.  I appreciate your thoughts on this one.
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Ted

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Posted 4 months ago

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Ted

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We have any engineers whom can help answer this?  Thanks.
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Stephen Williams, Employee

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In a PIM-SM network, a PIM router is required to be at all L3 hops you want multicast traffic to traverse.  IPMCForwarding is required for PIM so it will need to be enabled.  Also make sure routing works when you make the new network.
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Ted

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The network is currently extended via L2 vlan.  The cores have Layer 3 for this VLAN and VRRP is running on each.  When the dc670 got installed the vlan was built L2 and I want to configure a L3 interface for this VLAN.  I'm concerned that the current PIM source on the Layer 2 VLAN might start having problems.  I can draw this up for a quick review if this helps.   Thank you
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Stephen Williams, Employee

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So you have two cores doing all of your routing.  You installed the dc670 with L2 vlans to it.  You want a new routable vlan to go to this 670 to break up the L2 domain?  If routing is all done at the cores you should just need PIM on the Cores once the new vlan is routeable.

Have you seen this KCS article.https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-configure-PIM-sparse-mode-on-EXOS

I wrote it a while ago, and it explains PIM-SM and shows you how to configure it.  Read all of it and let me know if it answers some of your questions.
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Ted

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The source got moved to the layer 2 switch.  The RP is still on the the cores, I believe I need to move the RP down to the DC670's if I make the DC670's layer 3.  Seems like trouble if I want L3 on on these.  I appreciate the info and yes I've used it.