Linux 7 Multicast Configuration: Difference between revisions

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* If iptables runs on the system, allow multicast traffic for the interface that will handle multicast traffic: [[Iptables_Command_Line_Tool_Examples#Multicast|Configure iptables to allow Multicast]]
* If iptables runs on the system, allow multicast traffic for the interface that will handle multicast traffic: [[Iptables_Command_Line_Tool_Examples#Multicast|Configure iptables to allow Multicast]]
* Test it. For more details see the [[#Troubleshooting|Troubleshooting]] section.
* Test it. For more details see the [[#Troubleshooting|Troubleshooting]] section.
=/proc=
==/proc/net/dev_mcast==
Contains Layer2 multicast groups which a device is listening to (interface index, label, number of references, number of bound addresses).
==/proc/net/igmp==
Contains IPv4 multicast groups joined by this host.
==/proc/net/igmp6==
Contains IPv6 multicast groups joined by this host.


=Troubleshooting=
=Troubleshooting=

Revision as of 16:53, 21 March 2017

Internal

Concepts

Multicast

Procedure

Multicast at Kernel Level

Make sure multicast is enabled at kernel level.

To compile multicast support into the kernel, CONFIG_IP_MULTICAST must be present in the kernel configuration file.

Multicast Support at Interface Level

/proc

/proc/net/dev_mcast

Contains Layer2 multicast groups which a device is listening to (interface index, label, number of references, number of bound addresses).

/proc/net/igmp

Contains IPv4 multicast groups joined by this host.

/proc/net/igmp6

Contains IPv6 multicast groups joined by this host.

Troubleshooting

Display Multicast Group Membership Information

netstat -g

displays multicast group membership information for IPv4 and IPv6. Optionally use -n to prevent DNS lookups (faster).

The same information can be obtained from /proc:

cat /proc/net/dev_mcast
cat /proc/net/igmp
cat /proc/net/igmp6

Ping

Send Multicast Traffic

See

Java Network Traffic Generator

Organizatorium

TODO http://lartc.org/howto/lartc.multicast.html


echo 1 > /proc/sys/net/ipv4/ip_forward