GitHub user tobzsc added a comment to the discussion: EVPN-VXLAN - IPv6 via SLAAC
Finally, we found the problem which is related to VXLAN flags. When IPv6 multicast packets enter our fabric the VXLAN packet somehow gets the flags `0x0a00` instead of `0x0800`, which is being ignored by the kernel and the packet is dropped. See the corresponding code fragment here: https://elixir.bootlin.com/linux/v5.14.21/source/drivers/net/vxlan.c#L1905 This seems to be a problem with SONiC itself and we will check here further. The temporary fix is: ``` tc qdisc add dev ens1f0np0 clsact tc filter add dev ens1f0np0 ingress pref 1 proto ip flower ip_proto udp dst_port 4789 action pedit munge offset 28 u8 set 0x08 tc qdisc add dev ens1f1np1 clsact tc filter add dev ens1f1np1 ingress pref 1 proto ip flower ip_proto udp dst_port 4789 action pedit munge offset 28 u8 set 0x08 ``` GitHub link: https://github.com/apache/cloudstack/discussions/8685#discussioncomment-8568633 ---- This is an automatically sent email for users@cloudstack.apache.org. To unsubscribe, please send an email to: users-unsubscr...@cloudstack.apache.org
