Cannot ping ipv6 from remote container about kube-v6

[leblancd]

@bamb00:

• Check that each host node (i.e. not the pods) has IPv6 forwarding enabled using 'sysctl net.ipv6.conf.all.forwarding'.
• Check whether each node can ping6 to each other.
• I'm not an expert on Calico IPv6 setup, but this guide mentions that "If you wish to only use IPv6 (by disabling IPv4) or your hosts only have IPv6 addresses, you must disable autodetection of IPv4 by setting IP to none. With that set you must also pass a CALICO_ROUTER_ID to each calico-node pod."
• If everything checks out so far, you can try bringing up a couple of pods with alpine containers, and then install tshark in one or more of those alpine containers with 'apk add tshark'. Once tshark is installed, you would be able to do 'tshark -i eth0' to capture incoming packets on that pod's eth0 interface. You would then try ping6 from the other pod.
• (I haven't tried this on a Calico setup) If you're not seeing incoming pings or neighbor discovery exchanges on the remote pod (I suspect that you won't), you can then try installing tshark (or wireshark, or use tcpdump) on one or more host nodes, and then run tshark on the physical interfaces of each host node while one pod is ping6'ing the other pod, to see how far ping6/nd packets are going.

[leblancd]

@bamb00 - Any luck on the pings?