quagga-pimd-router# show running-config 

Current configuration:
!
hostname quagga-pimd-router
password zebra
enable password zebra
log stdout
!
interface eth0
 ip pim ssm
 ip igmp
!
interface eth2
 ip pim ssm
 ip igmp
!
interface lo
!
interface virbr0
!
!
ip multicast-routing
!
line vty
 exec-timeout 60 0
!
end

Router# show running-config 

Current configuration:
!
hostname Router
password zebra
enable password zebra
!
interface eth0
 no link-detect
 multicast
 ipv6 nd suppress-ra
!
interface eth2
 no link-detect
 multicast
 ipv6 nd suppress-ra
!
interface lo
 no link-detect
!
interface virbr0
 no link-detect
 ipv6 nd suppress-ra
!
ip forwarding
!
!
line vty
!
end

>route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         10.64.48.1      0.0.0.0         UG    0      0        0 eth0
10.64.48.0      *               255.255.255.0   U     1      0        0 eth0
10.64.50.0      *               255.255.255.0   U     1      0        0 eth2
192.168.122.0   *               255.255.255.0   U     0      0        0 virbr0
224.0.0.0       *               240.0.0.0       U     0      0        0 eth2
224.0.0.0       *               240.0.0.0       U     0      0        0 eth0

>grep -i multicast /boot/config-3.13.0-85-generic
CONFIG_IP_MULTICAST=y

>grep -i ip_mroute /boot/config-3.13.0-85-generic
CONFIG_IP_MROUTE=y
# CONFIG_IP_MROUTE_MULTIPLE_TABLES is not set

>sysctl -A | grep -i mc_forwarding
sysctl: permission denied on key 'fs.protected_hardlinks'
sysctl: permission denied on key 'fs.protected_symlinks'
sysctl: permission denied on key 'kernel.cad_pid'
sysctl: permission denied on key 'kernel.usermodehelper.bset'
sysctl: permission denied on key 'kernel.usermodehelper.inheritable'
net.ipv4.conf.all.mc_forwarding = 1
net.ipv4.conf.default.mc_forwarding = 0
net.ipv4.conf.eth0.mc_forwarding = 1
net.ipv4.conf.eth2.mc_forwarding = 1
net.ipv4.conf.lo.mc_forwarding = 0
net.ipv4.conf.virbr0.mc_forwarding = 0
sysctl: permission denied on key 'net.ipv4.tcp_fastopen_key'
net.ipv6.conf.all.mc_forwarding = 0
net.ipv6.conf.default.mc_forwarding = 0
net.ipv6.conf.eth0.mc_forwarding = 0
net.ipv6.conf.eth2.mc_forwarding = 0
net.ipv6.conf.lo.mc_forwarding = 0
net.ipv6.conf.virbr0.mc_forwarding = 0

>netstat -gn
IPv6/IPv4 Group Memberships
Interface       RefCnt Group
--------------- ------ ---------------------
lo              1      224.0.0.1
eth0            1      224.0.0.13
eth0            1      224.0.0.22
eth0            1      224.0.0.251
eth0            2      224.0.0.1
virbr0          1      224.0.0.251
virbr0          1      224.0.0.1
eth2            1      224.0.0.13
eth2            1      224.0.0.22
eth2            1      224.0.0.251
eth2            2      224.0.0.1
lo              1      ff02::1
lo              1      ff01::1
eth0            1      ff02::fb
eth0            1      ff02::1:ffbc:723d
eth0            1      ff02::1
eth0            1      ff01::1
virbr0          1      ff02::1
virbr0          1      ff01::1
eth2            1      ff02::fb
eth2            1      ff02::1:ff3c:76
eth2            1      ff02::1
eth2            1      ff01::1

• PC1 then PC2 doesn't receive multicast packets, PC3 doesn't receive multicast packets.
• PC2 then PC1 doesn't receive multicast packets, PC3 doesn't receive multicast packets
• PC3 then PC2 receive multicast packets, PC1 doesn't receive multicast packets

>route del -net 224.0.0.0 netmask 240.0.0.0 dev eth2

>route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         10.64.48.1      0.0.0.0         UG    0      0        0 eth0
10.64.48.0      *               255.255.255.0   U     1      0        0 eth0
10.64.50.0      *               255.255.255.0   U     1      0        0 eth2
192.168.122.0   *               255.255.255.0   U     0      0        0 virbr0
224.0.0.0       *               240.0.0.0       U     0      0        0 eth0

• PC1 then PC2 doesn't receive multicast packets, PC3 doesn't receive multicast packets.
• PC2 then PC1 doesn't receive multicast packets, PC3 receive multicast packets
• PC3 then PC2 receive multicast packets, PC1 doesn't receive multicast packets

>iperf -c 234.5.6.7 -u -T 64 -t 3000 -i 1

>iperf -s -u -B 234.5.6.7 -i 1

>route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
1.1.1.0         *               255.255.255.252 U     0      0        0 br0
2.0.0.0         *               255.0.0.0       U     0      0        0 br0
10.64.42.0      *               255.255.255.0   U     0      0        0 br0
10.64.43.0      *               255.255.255.0   U     0      0        0 br0
10.64.44.0      *               255.255.255.0   U     0      0        0 br0.1
10.64.45.0      *               255.255.255.0   U     0      0        0 br0.0
10.64.50.0      *               255.255.255.0   U     0      0        0 br0
224.0.0.0       *               240.0.0.0       U     0      0        0 br0

>route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.64.48.0      *               255.255.255.0   U     1      0        0 eth0
link-local      *               255.255.0.0     U     1000   0        0 eth0
224.0.0.0       *               240.0.0.0       U     0      0        0 eth0

Quote:

Originally Posted by pammud Did you add this entry in PC2 kernel routing table? 224.0.0.0 * 240.0.0.0 U 0 0 0 eth0 I believe PIMD should internally update the PC2 kernel routing table (which is not happening in my testing)

• Check KERNEL options connected with multicast
• Turn on IP Forwarding
• Start PIM Daemon
• Start sending from PC1 multicast packets (some group)
• Start receiving packets in PC3

Quote:

Originally Posted by break_da_funk Check KERNEL options connected with multicast Turn on IP Forwarding Start PIM Daemon Start sending from PC1 multicast packets (some group) Start receiving packets in PC3

• Required kernel options:

CONFIG_IP_MULTICAST=y
CONFIG_IP_MROUTE=y
CONFIG_IP_PIMSM_V1=y
CONFIG_IP_PIMSM_V2=y

Code:

cat /boot/config-`uname -r` | grep -i ip_mroute
cat /boot/config-`uname -r` | grep -i ip_multicast
cat /boot/config-`uname -r` | grep -i pim

• Multicast forwarding:

(change from br0 to your interface name)

Code:

cat /proc/sys/net/ipv4/conf/br0/mc_forwarding

• PIMD config:

Code:

#   This is the configuration file for "pimd", an IP multicast router.
#   pimd looks for it in "/etc/pimd.conf".
#
#   $Id: pimd.conf,v 1.17 2001/09/10 20:31:37 pavlin Exp $
#
#   Command formats:
##########
#phyint br0:0 disable
#phyint br0:1 disable
# default_source_preference <preference>
# default_source_metric <metric>
#
# phyint <local-addr | ifname> [disable|enable]  [threshold <t>] [preference <p>]
#                              [metric <m>]
#                              [altnet <net-addr> masklen <masklen>]
#                              [scoped <net-addr> masklen <masklen>]
#
# cand_rp [<local-addr>] [priority <number> ] [time <number>]
# cand_bootstrap_router [<local-addr>] [priority <number>]
# rp_address <rp-addr> [<group-addr> [masklen <masklen>] [priority <number>]]
#
# group_prefix <group-addr> [masklen <masklen>]
# group_prefix <group-addr> [masklen <masklen>]
# .
# .
# group_prefix <group-addr> [masklen <masklen>]
#
#
# switch_data_threshold [rate <number> interval <number>]
#
# switch_register_threshold [rate <number> interval <number>]
##########
# By default PIM will be activated on all interfaces.  Use phyint to 
# disable on interfaces where PIM should not be run.
#
# Preferences are used by assert elections to determine upstream routers.
# Currently pimd cannot reliably obtain preferences and metrics from the
# unicast routing protocols, so a default preference may be configured.
# In an assert election, the router advertising the lowest assert preference
# will be selected as the forwarder and upstream router for the LAN.
# 101 should be sufficiently high so that asserts from Cisco or GateD
# routers are prefered over poor-little pimd.
#
# It is reccommended that preferences be set such that metrics are never
# consulted.  However, default metrics may also be set and will default to
# 1024.
#
#
# A "phyint" can be specified by either its IP address or interface name.
#
# `preference` and `metric` after "phyint" are used to configure manually
# the default preference and metric for the Assert messages sent on that
# interface. Usually you don't need this, but if you do, think of them
# like `preference` and `metric` defined per iif, but used by the
# Asserts on the oifs.
#
# If you want to add "alternative (sub)net" to a physical interface,
# e.g., if you want to make incoming traffic with a non-local source address
# to appear as it is coming from a local subnet, then use the command:
#   phyint <local-addr | ifname> altnet <net-addr> masklen <len>
# XXX: if you use this command, make sure you know what you are doing!!
#
# If you want administrative scoped multicast filtering, use the
# following command:
#   phyint <local-addr | ifname> scoped <net-addr> masklen <masklen>
# This allows interfaces to be configured as an administrative boundary
# for the specified scoped address. Packets belonging to the scoped
# address will not be forwarded. To use this compile with -DSCOPED_ACL
# option (in Makefile).
# 
# `local-addr` after "cand_rp" and "cand_bootstrap_router" specifies
#  the local address to be used in the Cand-RP and Cand-BSR messages.
#  If not specified, the largest local IP address will be used (excluding
#  the disabled interfaces)
#
# `time` after `cand_rp` specifies how often to send the Cand-RP messages.
#  Its default value should be 60 seconds. Use smaller value for faster
#  convergence.
#
# `group_prefix` is/are the prefix(es) advertised if cand_rp
#
# It is possible to set a static Rendez-Vous Point using the "rp_address"
# setting.  The argument can be either a unicast or a multicast address
# followed by an optional group address and optional masklen to that.
#
# `rate` specifies the minimum rate in bits/s before the last hop
#  router or the RP switch to the shortest path (`switch_data_threshold`
#  and `switch_register_threshold` respectively)
#  `interval` specifies the interval for periodical testing of the rate
#  Currently, `interval` must be at least 5 (seconds)
#  XXX: Both intervals should be the same
#
#
#default_source_preference	101  # smaller is better
#default_source_metric		1024 # smaller is better

# The phyint setting MUST BE AFTER default_source_*,
# BUT MUST BE BEFORE everything else
# By default, all non-loopback multicast capable interfaces are enabled.
#phyint de1 disable

# Smaller value means "higher" priority
cand_rp time 30 priority 20

# Bigger value means  "higher" priority
cand_bootstrap_router priority 5

# Static rendez-vous point
#rp_address 192.168.10.1 224.0.0.0 masklen 8 priority 5

# All multicast groups
group_prefix 224.0.0.0 masklen 4

# 
spt_threshold		rate 50000 interval 20	# 50kbps (approx.)

• Send/receive multicast packets:

sender.c

Code:

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <time.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define HELLO_PORT 12345
#define HELLO_GROUP "225.0.0.37"

int main(int argc, char *argv[]) {
	struct sockaddr_in addr;
	int fd;
	char message[30];
	memset(message, '\0', 30);
	strcpy(message, "Hello world!");

	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
		perror("socket");
		exit(1);
	}
	unsigned char ttl = 32;
	setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
	
	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = inet_addr(HELLO_GROUP);
	addr.sin_port = htons(HELLO_PORT);
	double i = 0;
	
	const unsigned short int mes_size = strlen(message) + 10;
	char message_out[mes_size];
	while (1) {
		memset(message_out, '\0', mes_size);
		sprintf(message_out, "[%0.f] %s%c", i++, message, '\0');
		fprintf(stderr, "Message out=%s, length=%d\n", message_out, strlen(message_out));
		if (sendto(fd, message_out, strlen(message_out), 0,
				(struct sockaddr *) &addr, sizeof(addr)) < 0) {
			perror("sendto");
			exit(1);
		}
		sleep(1);
	}
	return 0;
}

listener.c

Code:

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <time.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define HELLO_PORT 12345
#define HELLO_GROUP "225.0.0.37"
#define MSGBUFSIZE 256

int main(int argc, char *argv[]) {
	struct sockaddr_in addr;
	int fd, nbytes;
	size_t addrlen;
	struct ip_mreq mreq;
	char msgbuf[MSGBUFSIZE];

	u_int yes = 1;

	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
		perror("Create socket");
		exit(1);
	}

	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
		perror("Reusing ADDR failed");
		exit(1);
	}

	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	addr.sin_port = htons(HELLO_PORT);

	if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		perror("Bind");
		exit(1);
	}

	mreq.imr_multiaddr.s_addr = inet_addr(HELLO_GROUP);
	mreq.imr_interface.s_addr = htonl(INADDR_ANY);
	if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq))
			< 0) {
		perror("Set socket option");
		exit(1);
	}

	while (1) {
		addrlen = sizeof(addr);
		memset(msgbuf, '\0', MSGBUFSIZE);
		if ((nbytes = recvfrom(fd, msgbuf, MSGBUFSIZE, 0,
				(struct sockaddr *) &addr, &addrlen)) < 0) {
			perror("Read from socket");
			exit(1);
		}
		puts(msgbuf);
	}
	return 0;
}

Make sure that You start sender/listener on machines with one interface - the programs run with default interfaces. If You want to use multi interface You have to modify sender/listener according to 6.3 point in this document.

> sysctl -A | grep -i mc_forwarding
net.ipv4.conf.all.mc_forwarding = 1
net.ipv4.conf.br0.mc_forwarding = 1
net.ipv4.conf.default.mc_forwarding = 0
net.ipv4.conf.eth0.mc_forwarding = 0
net.ipv4.conf.eth1.mc_forwarding = 0
net.ipv4.conf.lo.mc_forwarding = 0
net.ipv4.conf.pimreg.mc_forwarding = 1

> cat /proc/net/ip_mr_cache 
Group    Origin   Iif     Pkts    Bytes    Wrong Oifs
250000E1 8030400A -1         0        0        0