Feature #11954


Multicast limits

Added by Guillaume LUCAS 2 months ago. Updated 2 months ago.

IGMP Proxy
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On my two XG-1541, I have configured 1 LAGG, 67 VLANs on this LAGG, 67 networks interfaces and I want to use inter-VLANs multicast.

Multicast accross VLANs works with igmpproxy on pfSense <= 21.02.2-RELEASE but there are several cumulative constraints:

  • Only one upstream interface so only one VLAN can send multicast at once. * In theory, pimd (available in additionnal package) permits several upstream interfaces but it's totally buggy: 1) when we start it, it tries to bind() on each network interface so it exceeds MAXVIFS kernel value - 32 - so it crashes. For more information, please see . 2) It ignores its configuration file in which we have disabled unwanted network interfaces and it still tries to bind() on all interfaces.
  • Only 32 VLANs with multicast enabled at the same time (upstream + downstreams) in the best case scenario. Cause: MAXVIFS = 32 in FreeBSD kernel. * When we add CARP on each VLAN, the limit becomes 16 multicast-VLANs activable in igmpproxy. Cause: igmpproxy sees each CARP VIP as a network interface so it tries to bind() on it and reaches MAXVIFS. * The more VIP we add on multicast-enabled interfaces, the less number of multicast-available interfaces we have. Same cause. * In my use case, I reach this limit of 16 multicast-enabled networks. It is annoying and no future-proof (from a network expansion perspective).
  • A multicast-enabled interface can't have more than six VIPs on it. Otherwise igmpproxy refuses to start. Cause: ???
  • A multicast-enabled VLAN must be in the XX first VLANs listed in Interface > Assignments > VLANs. Otherwise igmpproxy don't bind() on it (no log message "adding VIF, Ix XX Fl 0x0 IP 0xXXXXXXXX lagg0.XXX). Cause: ??? * On fresh install XX = 22. With CARP (for routing purpose) on all of our VLANs, XX = 21 (obviously, only VIPs on multicast-enabled VLANs are counted). With CARP for routing and destination NAT, XX = 20. If we add additionnal VIPs on these multicast-enabled VLANs, XX = 19. * This limit is especially annoying! I want to sort my networks by usage (servers, users, administration, etc.), not by a sort order imposed by igmpproxy.

For more information, please see .

Can you fix these limits, please?

IMO, at this time, pfSense don't offer enterprise-grade multicast. I think so because I have a basic network (no use of network advanced features, small number of users, small troughput, etc.), so, if I reach several limits (see above), many others enterprises will reach them. I fit the marketing target of pfSense, but not on inter-VLANs multicast, so I think that the multicast features of pfsense are below the expectations of the marketing target. Here is my justification for this feature request.


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