172.31.0.2 (00:19:e8:2b:25:00) – vlan address on switch to which multicast source is connected
172.31.0.1 (00:21:1c:37:d4:44) – vlan address on intermediate switch/vlan
KVM Guest network config
--------------------------
Code: Select all
[root@vcentos68a ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:e6:5c:10 brd ff:ff:ff:ff:ff:ff
inet 10.86.67.218/21 brd 10.86.71.255 scope global eth1
3: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:68:c6:f3 brd ff:ff:ff:ff:ff:ff
inet 172.31.0.14/16 brd 172.31.255.255 scope global eth2
4: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:28:61:94 brd ff:ff:ff:ff:ff:ff
[root@vcentos68a ~]# cat /etc/sysconfig/network-scripts/route-eth2
224.0.0.0/4 via 172.31.0.1 dev eth2
[root@vcentos68a ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.86.64.0 * 255.255.248.0 U 0 0 0 eth1
172.31.0.0 * 255.255.0.0 U 0 0 0 eth2
link-local * 255.255.0.0 U 1002 0 0 eth1
link-local * 255.255.0.0 U 1003 0 0 eth2
224.0.0.0 172.31.0.1 240.0.0.0 UG 0 0 0 eth2
default 10.86.64.1 0.0.0.0 UG 0 0 0 eth1
[root@vcentos68a ~]#
[root@vcentos68a ~]# sysctl -a | grep eth2 | grep -v ipv6 | grep -e rp -e igm
net.ipv4.conf.eth2.rp_filter = 0
net.ipv4.conf.eth2.proxy_arp = 0
net.ipv4.conf.eth2.arp_filter = 0
net.ipv4.conf.eth2.arp_announce = 0
net.ipv4.conf.eth2.arp_ignore = 0
net.ipv4.conf.eth2.arp_accept = 0
net.ipv4.conf.eth2.arp_notify = 0
net.ipv4.conf.eth2.proxy_arp_pvlan = 0
net.ipv4.conf.eth2.force_igmp_version = 3
[root@vcentos68a ~]#
[root@vcentos68a ~]# cat /etc/sysconfig/iptables | grep -e cast -e ig
-A INPUT -p igmp -j ACCEPT
-A OUTPUT -p igmp -j ACCEPT
-A INPUT -m pkttype --pkt-type multicast -j ACCEPT
-A OUTPUT -m pkttype --pkt-type multicast -j ACCEPT
-A INPUT -m pkttype --pkt-type unicast -j ACCEPT
[root@vcentos68a ~]#
KVM Host network config:
-------------------------
Code: Select all
[root@b16 ~]# ip addr
…
2: enp8s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master br-enp8s0f0 state UP qlen 1000
link/ether 00:1e:67:d8:99:e2 brd ff:ff:ff:ff:ff:ff
inet6 fe80::21e:67ff:fed8:99e2/64 scope link
valid_lft forever preferred_lft forever
3: enp8s0f1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master br-enp8s0f1 state UP qlen 1000
link/ether 00:1e:67:d8:99:e3 brd ff:ff:ff:ff:ff:ff
inet6 fe80::21e:67ff:fed8:99e3/64 scope link
valid_lft forever preferred_lft forever
…
6: br-enp8s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
link/ether 00:1e:67:d8:99:e2 brd ff:ff:ff:ff:ff:ff
inet 10.86.67.198/21 brd 10.86.71.255 scope global dynamic br-enp8s0f0
valid_lft 596421sec preferred_lft 596421sec
inet6 fe80::21e:67ff:fed8:99e2/64 scope link
valid_lft forever preferred_lft forever
7: br-enp8s0f1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
link/ether 00:1e:67:d8:99:e3 brd ff:ff:ff:ff:ff:ff
inet 172.31.0.11/16 brd 172.31.255.255 scope global dynamic br-enp8s0f1
valid_lft 250829sec preferred_lft 250829sec
inet6 fe80::21e:67ff:fed8:99e3/64 scope link
valid_lft forever preferred_lft forever
8: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
link/ether 52:54:00:0d:d8:b3 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
valid_lft forever preferred_lft forever
9: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 1000
link/ether 52:54:00:0d:d8:b3 brd ff:ff:ff:ff:ff:ff
19: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master virbr0 state UNKNOWN qlen 1000
link/ether fe:54:00:28:61:94 brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc54:ff:fe28:6194/64 scope link
valid_lft forever preferred_lft forever
20: vnet1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br-enp8s0f0 state UNKNOWN qlen 1000
link/ether fe:54:00:e6:5c:10 brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc54:ff:fee6:5c10/64 scope link
valid_lft forever preferred_lft forever
21: vnet2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br-enp8s0f1 state UNKNOWN qlen 1000
link/ether fe:54:00:68:c6:f3 brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc54:ff:fe68:c6f3/64 scope link
valid_lft forever preferred_lft forever
[root@b16 ~]#
Code: Select all
No Time Src Dst Dst Mac Addr Proto Len Info
26 34.471585 172.31.0.2 224.0.0.1 01:00:5e:00:00:01 IGMPv2 60 Membership Query, general
27 36.096534 172.31.0.14 224.0.0.2 01:00:5e:00:00:02 IGMPv2 46 Leave Group 239.195.170.85
28 36.099678 172.31.0.14 239.195.170.85 00:21:1c:37:d4:44 IGMPv2 46 Membership Report group 239.195.170.85
However if the network interface eth2 (172.31.0.14) is toggled (down-up), the multicast is received for about a minute before it stops. This seems because of a single join from (10.86.67.218) that goes through eth2 with a multicast mac address. The dst mac address for the joins from 172.31.0.14 remain targeted to 172.31.0.1. Why is it that we see this solitary join from 10.86.67.218?
Code: Select all
No Time Src Dst Dst Mac Addr Proto Len Info
24 32.486959 172.31.0.14 224.0.0.2 01:00:5e:00:00:02 IGMPv2 46 Leave Group 239.195.170.85
25 32.489530 172.31.0.14 239.195.170.85 00:21:1c:37:d4:44 IGMPv2 46 Membership Report group 239.195.170.85
26 33.289447 10.86.67.218 239.195.170.85 01:00:5e:43:aa:55 IGMPv2 46 Membership Report group 239.195.170.85
27 78.031852 172.31.0.2 224.0.0.1 01:00:5e:00:00:01 IGMPv2 60 Membership Query, general
28 85.104750 172.31.0.14 239.195.170.85 00:21:1c:37:d4:44 IGMPv2 46 Membership Report group 239.195.170.85