S32GのトピックRe: IGMP Snooping with SJA1110

IGMP Snooping with SJA1110

sg_cnh — Wed, 05 Nov 2025 16:25:18 GMT

Hello,

I have an S32G with SJA1110 running bsp43 and am trying to enable IGMP snooping to dynamically route multicast streams. I have identified a few unique issues related to IGMP which I am not sure how to resolve. I have confirmed that disabling IGMP snooping causes multicast packets to flood the switch, so the IGMP snooping option is doing something... Just not the expected behavior.

Multicast traffic is always forwarded to the lowest enumerated active port
1. A stream egressing on port 4 with a node on port 3 requesting that traffic through IGMP will cause traffic to egress through port 1 (if that link is active) as if port 1 had requested the traffic. If the port 1 link is not active, traffic will be forwarded to port 2 if that link is active.
2. I am able to manually route the traffic with mdb, but my expectation is that IGMP snooping should be managing this automatically
Enabling multicast-querier does not cause membership queries to egress the switch ports
1. There are IGMP queries on the DSA bridge interface, but no IGMP queries are visible on other links connected to the switch
2. I suspect I may need to set up a tc rule to trap IGMP queries from the bridge port and redirect them to the switch ports?

I'm not clear if this is some issue with Linux configuration or a limitation from switch hardware.

Thanks for any suggestions.

Re: IGMP Snooping with SJA1110

alejandro_e — Wed, 05 Nov 2025 22:16:10 GMT

Hello @sg_cnh,

Thanks for reaching out to us. About your question, the IGMP is not a feature we can support in the S32G community, as far as I can tell the IGMP is done over IP, it is not related to the S32G itself, I checked the GMAC, PFE modules and the SJA1110 chip and none of them include direct support or examples for that feature. You may get some guidance in Other-NXP-Products, where the support engineers for the SJA1110 can help you.

I apologize for the inconveniences.

Re: IGMP Snooping with SJA1110

sg_cnh — Wed, 05 Nov 2025 22:25:26 GMT

Thanks for the reply. I have reposted to the other forum you suggested.

Re: IGMP Snooping with SJA1110

alejandro_e — Thu, 06 Nov 2025 19:33:22 GMT

Hello @sg_cnh,

Thanks for understanding and reposting your question in the other forum.

Let me know if there is something else you need support with.