topic Re: Layer 2 multicast in SDA in Software-Defined Access (SD-Access)

Layer 2 multicast in SDA

e-chuah — Mon, 31 Jul 2023 13:50:59 GMT

Hi,

I would like to understand if there is any specific configuration i need to do for Layer 2 multicast on SDA.

Layer 2 multicast => Both source(sender) and destination(receiver) on the same vlan (but connected to different fabric edge switch).

We already enabled multicast in the underlay using LAN automation. We can see RP, pim sparse mode etc enabled in the underlay. We also enable Layer 2 flooding for that vlan. Any other configuration required for Layer 2 multicast to work?

My understanding is that there is no need to turn on overlay L3 multicast like what is shown in
https://community.cisco.com/t5/networking-knowledge-base/cisco-sd-access-multicast/ta-p/4068110

Do let me know if this understanding is not correct.

Thanks

Eng Wee

Re: Layer 2 multicast in SDA

Andrii Oliinyk — Mon, 31 Jul 2023 16:32:33 GMT

not sure what section u refer in the above URL with "turn on overlay L3 multicast", but basically your case is last one in "Multicast in SDA TZ Doc v0.6 .pdf" (easy googled) & what u need for this is to use native multicast.

Re: Layer 2 multicast in SDA

jedolphi — Tue, 01 Aug 2023 07:20:13 GMT

If the access VLAN has an Anycast Gateway (an SVI on the Fabric Edge Nodes) then you need to enable multicast routing in the L3VN for any multicast with a TTL of >1, not Layer 2 Flooding. Use the SD-Access Multicast Configuration Workflow in DNA Center. Regards, Jerome

Re: Layer 2 multicast in SDA

e-chuah — Tue, 01 Aug 2023 07:35:15 GMT

Yes..Thanks Jerome and Andy... Managed to get it working after doing a bit more research in Cisco live sessions...

The session Demystifying IP Multicast in SD-Access – BRKENS-2820 helps a lot.

Re: Layer 2 multicast in SDA

Andrii Oliinyk — Tue, 01 Aug 2023 07:44:06 GMT

good luck