From ff050a291656a491748f2af2608c48b9ff803d26 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Linus=20L=C3=BCssing?= Date: Sat, 21 Sep 2019 23:36:55 +0200 Subject: [PATCH] docs: gluon-mesh-batman-adv: note regarding IGMP/MLD snooping switches This adds a warning that entprise switches with an IGMP/MLD snooping feature are not supported yet with IGMP/MLD filtering enabled. For this to work, firstly the Linux bridge on the Gluon node needs to support Multicast Router Discovery (RFC4286). But this feature was only added to the Linux kernel recently, in 5.1. Secondly, a Gluon node would need to periodically send "Multicast Router Advertisment" (RFC4286) messages, to "announce" the multicast router port setting on bridge port bat0. Thirdly, the IGMP/MLD snooping switches would need to implement RFC4286. --- docs/package/gluon-mesh-batman-adv.rst | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/docs/package/gluon-mesh-batman-adv.rst b/docs/package/gluon-mesh-batman-adv.rst index 966cd7ab..0e24f344 100644 --- a/docs/package/gluon-mesh-batman-adv.rst +++ b/docs/package/gluon-mesh-batman-adv.rst @@ -197,6 +197,12 @@ assume that there is no multicast router behind this port, meaning to only forward multicast to this port if an according multicast listener on this link was detected. +Further limitations: IGMP/MLD snooping switches (e.g. "enterprise switches") +behind the client network of a node (LAN ports) are unsupported. It is +advised to disable IGMP/MLD snooping on those enterprise switches for now +or to at least manually mark the port to the Gluon router as a +"multicast router port". + Alternatively, the filtering of IGMP/MLD reports can be disabled via the site.conf (which is not recommended in large meshes though). See :ref:`site.conf mesh section ` for details.