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Packets can't go from router inner interface to vm

I got a very strange behavior that drived me crazy a whole day:

  • I assign a VM with a floating IP.
  • From the VM, I can ping to the internet OK.
  • From the outside random host, I can't ping to the VM.

Then I start tcpdump to see waht happened. On neutron router:

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf tcpdump -i qg-0103d6fa-31
15:58:09.913759 IP 146.187.3.109.rev.sfr.net > 46.105.252.218: ICMP echo request, id 47245, seq 126, length 64

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf tcpdump -i qr-343ab2cb-f5

15:56:40.209776 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 37, length 64
15:56:41.217209 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 38, length 64
15:56:42.225567 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 39, length 64

I got the ICMP request on both interfaces of the ex-router, so everything is OK.

But on the VM, I got no ICMP request, only get repeatively ARP request. The VM did reply its MAC address. I checked ARP table on router and found that it got MAC address of VM OK (192.168.100.44):

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf arp                         
Address                  HWtype  HWaddress           Flags Mask            Iface
vss-gw-6k.fr.eu          ether   00:07:b4:00:00:02   C                     qg-0103d6fa-31
192.168.100.44           ether   fa:16:3e:38:69:78   C                     qr-343ab2cb-f5

Strangely, the VM received no ICMP after all. I don't know how to debug this case any more. Please help me with some leads.

Packets can't go from router inner interface to vm

I got a very strange behavior that drived me crazy a whole day:

  • I assign a VM with a floating IP.
  • From the VM, I can ping to the internet OK. OK.
  • From the outside random host, I can't ping to the VM.

Then I start tcpdump to see waht happened. On neutron router:

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf tcpdump -i qg-0103d6fa-31
15:58:09.913759 IP 146.187.3.109.rev.sfr.net > 46.105.252.218: ICMP echo request, id 47245, seq 126, length 64

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf tcpdump -i qr-343ab2cb-f5

15:56:40.209776 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 37, length 64
15:56:41.217209 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 38, length 64
15:56:42.225567 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 39, length 64

I got the ICMP request on both interfaces of the ex-router, so everything is OK.

But on the VM, I got no ICMP request, only get repeatively ARP request. The VM did reply its MAC address. I checked ARP table on router and found that it got MAC address of VM OK (192.168.100.44):

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf arp                         
Address                  HWtype  HWaddress           Flags Mask            Iface
vss-gw-6k.fr.eu          ether   00:07:b4:00:00:02   C                     qg-0103d6fa-31
192.168.100.44           ether   fa:16:3e:38:69:78   C                     qr-343ab2cb-f5

Strangely, the VM received no ICMP after all. I don't know how to debug this case any more. Please help me with some leads.

Packets can't go from router inner interface to vm

I got a very strange behavior that drived me crazy a whole day:

  • I assign a VM with a floating IP.
  • From the VM, I can ping to the internet OK.
  • From the outside random host, I can't ping to the VM.

Then I start tcpdump to see waht happened. On neutron router:

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf tcpdump -i qg-0103d6fa-31
15:58:09.913759 IP 146.187.3.109.rev.sfr.net > 46.105.252.218: ICMP echo request, id 47245, seq 126, length 64

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf tcpdump -i qr-343ab2cb-f5

15:56:40.209776 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 37, length 64
15:56:41.217209 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 38, length 64
15:56:42.225567 IP 146.187.3.109.rev.sfr.net > 192.168.100.44: ICMP echo request, id 47245, seq 39, length 64

I got the ICMP request on both interfaces of the ex-router, so everything is OK.

But on the VM, I got no ICMP request, only get repeatively ARP request. The VM did reply its MAC address. I checked ARP table on router and found that it got MAC address of VM OK (192.168.100.44):

sudo ip netns exec qrouter-f918cbb7-dc0c-4713-a6f5-3c66b46e12cf arp                         
Address                  HWtype  HWaddress           Flags Mask            Iface
vss-gw-6k.fr.eu          ether   00:07:b4:00:00:02   C                     qg-0103d6fa-31
192.168.100.44           ether   fa:16:3e:38:69:78   C                     qr-343ab2cb-f5

Strangely, the VM received no ICMP after all. I don't know how to debug this case any more. Please help me with some leads.

UPDATE: I don't know if it is the case or not: the mac address of the tap device (on compute node) and the corresponding interface on VM is off:

tap:

tap2e901035-a4 Link encap:Ethernet  HWaddr fe:16:3e:be:28:23

interface on VM:

HWaddr fa:16:3e:be:28:23