Description of problem: Pods can not receive multicast from other pods which are in the same namespace but different node. Same testing will pass in SDN cluster. Version-Release number of selected component (if applicable): 4.5.0-0.nightly-2020-06-03-105031 How reproducible: Always Steps to Reproduce: 1.oc new-project multicast-test 2.oc annotate namespace multicast-test k8s.ovn.org/multicast-enabled="true" 3.oc create -f https://raw.githubusercontent.com/weliang1/Openshift_Networking/master/Features/Pod/multicast-pod.yaml 4.Run below cmd in the two pods which are int the different nodes: omping -m 239.255.254.24 $pod1IP $pod2IP Actual results: Expected results: Both pods can join multicast group 239.255.254.24 and receive muticast traffic Additional info: #From SDN cluster sh-4.2# tcpdump -nvvvv -i ens3 -een | grep 239.255.254.24 tcpdump: listening on ens3, link-type EN10MB (Ethernet), capture size 262144 bytes 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.129.2.22.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 sh-4.2# tcpdump -nvvvv -i vxlan_sys_4789 -een | grep 239.255.254.24 tcpdump: listening on vxlan_sys_4789, link-type EN10MB (Ethernet), capture size 262144 bytes 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.131.0.26.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 10.129.2.22.4321 > 239.255.254.24.4321: [udp sum ok] UDP, length 69 # From OVN cluster: sh-4.2# tcpdump -nvvvv -i ens3 -een | grep 239.255.254.24 tcpdump: listening on ens3, link-type EN10MB (Ethernet), capture size 262144 bytes ^C1090 packets captured 1123 packets received by filter 0 packets dropped by kernel sh-4.2# tcpdump -nvvvv -i genev_sys_6081 -een | grep 239.255.254.24 tcpdump: listening on genev_sys_6081, link-type EN10MB (Ethernet), capture size 262144 bytes ^C118 packets captured 124 packets received by filter 0 packets dropped by kernel
Hi Aniket, Tested in 4.6.0-0.nightly-2020-08-05-082458: multicast not work at all Reproduce this bug in 4.5.0-0.nightly-2020-08-03-123303: Multicast works between the pods in the same node. Multicast not work between the pods in the different nodes.
@Dumitru has a fix for this. We need to pull that and point ovn-kubernetes to the build that has the patch.
Tested and verified in 4.6.0-0.nightly-2020-09-12-230035
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (OpenShift Container Platform 4.6 GA Images), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:4196