SPBM MULTICAST BETWEEN TWO FABRIC

[EF]

Hi Team,

I want to configure multicast between two fabric linked by legacy trunk of VLANs, they are two different fabrics not a multiarea fabric.

It´s multicast at L2, igmp snooping , the senders and receivers will be in both fabric distributed aleatory.

Is this topology supported? Any tips to configure it?

For ip igmp snooping inside a single fabric I configure:

At global level:

router isis
spbm 1 multicast enable

At VLAN level:

interface vlan XX
ip igmp proxy
ip igmp snooping

But I dont know how to inyect multicast traffic between them.

Regards

EF

[WillyHe]

Hello EF,

The disadvantage of the static solution is that ALL MCAST traffic (that is statically configured) is forwarded over the trunk to the other fabric and consuming bandwidth, also for which there is no receiver on the other side.

When this bandwidth consumption is a problem then you must setup a SPBM-PIM Gateway between the fabrics.

regards
WillyHe

[jerrygen]

Hi EF,

Yes, it’s possible, but since they’re separate fabrics linked by legacy VLAN trunks, you’ll likely need multicast routing or IGMP proxying between the cores. IGMP snooping alone won’t forward across fabrics—consider using PIM or a Layer 3 multicast gateway between them.

Regards

[WillyHe · Accepted solution]

Hi EF,

A quick and simple way is to statically forward all MCAST's from Fabric 1 to Fabric 2 and from Fabric 2 to Fabric 1, to that you configure static-group membership in the vlan interface towards port(s).
You can specify group address per group address to be forwarded or group address ranges to one or more ports.
Disadvantage is that existing streams are always forwarded over the link.

interface Vlan 1000
ip igmp static-group 239.0.0.1 239.0.0.1 1/9,1/11 static
ip igmp static-group 239.0.0.5 239.0.0.8 1/11 static
exit

regards
WillyHe

[EF]

Hi WillyHe,

Thanks for your tips for Im not able configure it, this is my lab:

But SW MAD1 doenst "see" sender or recivers, and if I try configure the statis groups under int vlan (Vlan200);

Thanks in advance for your answers.

Cheers!!

EF