topic Multicast is not working over the fabric in ExtremeSwitching (VSP/Fabric Engine)

Multicast is not working over the fabric

difan — Fri, 14 Jun 2024 23:24:09 GMT

I have VLAN 100 and the interface is in the GRT with IP 10.0.100.1. I have VLAN5 in VRF IPTV with IP 10.0.5.1. Here is my relevant config. I am testing multicast on VLAN 5 and VLAN 100. VLAN 100 interface is in the GRT and VLAN 5 is in VRF IPTV. The unicast works as expected.

router isis
spbm 1 multicast enable
spbm 1 ip enable

ip vrf iptv vrfid 1

router vrf iptv
ipvpn
i-sid 5000
mvpn enable
ipvpn enable

vlan i-sid 5 500
interface Vlan 5
vrf iptv
ip address 10.0.5.1 255.255.255.0 2
ip spb-multicast enable
ip igmp upnp-filter


vlan i-sid 100 1000
interface Vlan 100
ip address 10.0.100.1 255.255.255.0 1
ip spb-multicast enable
ip igmp upnp-filter

I use Cisco router to simulate the end devices. I joined 239.0.100.1 on VLAN 100 and 239.0.5.1 on VLAN5. Then I ping the multicast addresses from another router. I am getting responses on VLAN 100 but not on VLAN5. However, even for the VLAN 100 one, I don't see entries in the multicast-fib. I don't see IGMP group information with "show IP igmp group" command. I did packet capture and I do see querier message from the Fabric router and the join message from the Cisco. My understanding is that a dynamic I-SID should be generated for each (S,G). But in the "show i-sid" command, no matter how many groups I ping, I only see this one entry. I don't even know if it is related to my multicast.

ISID ISID PORT MLT ORIGIN ISID
ID TYPE VLANID INTERFACES INTERFACES NAME
---------------------------------------------------------------------------------------------------------

16777001 ELAN N/A - - C --- - --- - - -- FAN-ISID

Could you help me figure out what I did wrong here? Thanks!

Re: Multicast is not working over the fabric

WillyHe — Sat, 15 Jun 2024 14:41:15 GMT

First of all, MCAST traffic is NOT forwarded between VRF's, this would be a security breach, that is the main usage of VRF's.
So a response in vlan 100 is normal and NO response from vlan 5 is also normal because in another VRF.

To see which MCAST groups are known use the "show isis spb-mcast-summary" command.
To see GROUP information use the command in the GRT "show ip igmp group" int a VRF "show ip igmp group vrf VRFNAME" or "show ip igmp group vrfids VRFID", with the last you can provide multiple VRFID's.

Re: Multicast is not working over the fabric

difan — Sat, 15 Jun 2024 17:24:28 GMT

Thanks Willy! Sorry for not being clear but I didn't try to route multicast between the VRFs. I have two multicast streams/senders, one on each VLAN and I have two receivers too. There is to multicast hopping over VLANs.

My "show isis spb-mcast-summary" is empty on the BEB that connects to the multicast source...

My "show ip igmp group vrf iptv" is also empty on the BEB that connects to the multicast receiver...

I also did a packet capture. I see the IGMP querier messages from the BEB and the Join/leave message from the receiver.

The ping works but I feel that it works in a "broadcast" manner... Did I miss some command to have it properly enabled on the VRF?

In addition, "show isis lsdb tlv 185" is empty too...

Thanks!

Re: Multicast is not working over the fabric

EXTR_Paul — Mon, 17 Jun 2024 14:25:21 GMT

Your config looks good.

What are you using to generate the IGMP/Multicast traffic?

Are you doing this locally on a single switch? VSP or UH?

Is SPBm/ISIS running?

Re: Multicast is not working over the fabric

difan — Wed, 19 Jun 2024 01:14:44 GMT

Thanks, Paul, for your response. I am from the Cisco/Juniper world so I used a Cisco router for generating the multicast ping (ping 239.1.1.1) and another Cisco router for receiving the multicast (ip igmp join group 239.1.1.1).

I am testing on the EVENG virtual platform and I have a feeling that it is not as reliable. For example, I need to reboot from time to time or nothing would work. But to answer your question, yes, the SPBm/ISIS is running. I used the script (run spbm) to configure and I answered "yes" for multicast. Unicast works as expected. ISIS DB looks OK too for MAC addresses...

I will see if I can get a couple real switch to test and report back. Thanks!

Re: Multicast is not working over the fabric

EXTR_Paul — Wed, 19 Jun 2024 12:37:15 GMT

Yes. the virtual images of VOSS have several documented data plane limitations. I believe this is one of them.

This will 100% work on the real switches.