Bug 215806

Summary:	bridge can not receive self send igmp query if multicast_query_use_ifaddr set to 1,no firewall
Product:	Networking	Reporter:	shixudong
Component:	Other	Assignee:	Stephen Hemminger (stephen)
Status:	RESOLVED ANSWERED
Severity:	normal
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	5.15.32，5.10.0-13	Subsystem:
Regression:	No	Bisected commit-id:

Description shixudong 2022-04-05 10:12:56 UTC

no firewall 
bridge can not receive self send igmp query if 
echo 1 > /sys/class/net/br0/bridge/multicast_querier
echo 1 > /sys/class/net/br0/bridge/multicast_query_use_ifaddr

bridge can receive self send igmp query if
echo 1 > /sys/class/net/br0/bridge/multicast_querier
echo 0 > /sys/class/net/br0/bridge/multicast_query_use_ifaddr

Comment 1 shixudong 2022-04-07 10:39:01 UTC

and if i run alone igmp-querier from http://code.google.com/p/perl-igmp-querier/     
with the same ifaddr on the same linux and 
echo 0 > /sys/class/net/br0/bridge/multicast_querier

bridge can receive self send igmp query 

This proves to have nothing to do with firewall and RP_filter

I doubt if multicast_query_use_ifaddr=1,the igmp query packet bypass kernel

Comment 2 shixudong 2022-05-05 02:33:46 UTC

set net.ipv4.conf.all.accept_local to 1 solved the problem

igmp-querier send query to self by local interface,so not need accept_local to 1