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Forum Discussion
IGMP/MLD version incompatibility between M5300 switches
Hi all, I'm facing a strange problem and start to think that this is a firmware issue. But as I'm not 100% sure if I got all the concepts/RFCs right, I might also be wrong so I decided to start t...
Hi dialsc
Thank you for the thorough description of your issue above.
At this stage our Engineering team is tentatively reproducing your setup on M5300 Managed switches and we will get back to you shortly.
Let me tell you that RFC 3376 expects some limitations in Multicast Router behavior: for instance in 7.3.1 section we show that if ANY older version of IGMP are present on routers, the querier MUST use the lowest version of IGMP present on the network. But again thank you for the details, we are checking the real behavior on M5300 as I speak.
Regards,
Hi Laurent,
Thank you for your answer. Please note that I would be happy to support your engineers with what-ever I can, just let me know.
Regarding chapter 7.3.1 of RFC 3376. As I understand it, it describs how the Multicast Router should handle different versions of IGMP. The problem I'm facing seems to be the other way around to me. It's not the Multicast Router having problems but the Layer 2 switch's IGMP Snooping which does not work if the MCast Router sends out IGMP Queries in version 3. In fact, at least for IPv4, the multicast group is being listed in the MCast Table at the MCast Router (Routing/Multicast) as soon as the Multicast sender starts to send and eventhough this entry is missing on the Access Switch's MFDB.
This by the way does not apply to IPv6 multicast. This one is very interessting. The MCast Table of the Multicast Router is always empty. There is never ever a single entry available regardless of what version of MLD is being used by the querier. This - by the way - looks to me to be another strang thing on the M5300.
But again, let me know how I can help, pls.
Best regards,
dialsc
Hi dialsc
On behalf of our Engineering team:
We have setup the same environment as yours and everything works correctly no matter which version of IGMP/MLD.
The behavior is correct between Mrouter and Querier on M5300: we can test all V1/V2/V3 version on IGMP and V1/V2 on MLD using traffic generator.
Could you please send the multicast application name and version to us which is used on your MS Windows PCs?
Such as:
VLC
Version: 2.2.4.0
Otherwise ,The configuration file will also help us to resolve your concern.
Please following this guide to send it to us.
How do I send diagnostic files from my Managed Switch to NETGEAR community moderators
Regards,
Hi Laurent,
Thanks again. This pic looks different from my setup. Give me a moment to grap together all the files. I will send it out to the email address described soon.
The application to test multicast I use is called MultiCastor 3.0. I will add it in a zipped form to the email, thus it contains the config I'm running for the sender. The receiver can be simulated using the same tool listening to the according multicast groups.
Greez,
dialsc
Thank you. Please also send the Application name, version number and all relevant information on your software application generating multicast traffic.
Laurent
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