On VirtualBox [root@node-17 ~]# tcpdump -pnevvi eth0 vlan tcpdump: WARNING: eth0: no IPv4 address assigned tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes 12:58:03.237708 fa:16:3e:b8:f7:86 > Broadcast, ethertype 802.1Q (0x8100), length 46: vlan 1030, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.111.1 tell 192.168.111.2, length 28 12:58:04.237069 fa:16:3e:b8:f7:86 > Broadcast, ethertype 802.1Q (0x8100), length 46: vlan 1030, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.111.1 tell 192.168.111.2, length 28 [root@node-17 ~]# tcpdump -pnevvi eth0 vlan tcpdump: WARNING: eth0: no IPv4 address assigned tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes 12:58:03.237708 fa:16:3e:b8:f7:86 > Broadcast, ethertype 802.1Q (0x8100), length 46: vlan 1030, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.111.1 tell 192.168.111.2, length 28 12:58:04.237069 fa:16:3e:b8:f7:86 > Broadcast, ethertype 802.1Q (0x8100), length 46: vlan 1030, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.111.1 tell 192.168.111.2, length 28 12:58:05.252938 fa:16:3e:b8:f7:86 > Broadcast, ethertype 802.1Q (0x8100), length 46: vlan 1030, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.111.1 tell 192.168.111.2, length 28 on node-16 where is 192.168.111.2 [root@node-15 ~]# ip netns exec qdhcp-87c14191-4621-44bc-9290-4243c1457b36 ip a 39: tap63298197-85: mtu 1500 qdisc noqueue state UNKNOWN link/ether fa:16:3e:b8:f7:86 brd ff:ff:ff:ff:ff:ff inet 192.168.111.2/24 brd 192.168.111.255 scope global tap63298197-85 inet6 fe80::f816:3eff:feb8:f786/64 scope link valid_lft forever preferred_lft forever 40: lo: 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 inet6 ::1/128 scope host valid_lft forever preferred_lft forever [root@node-15 ~]# tcpdump -pnevvvi eth0 vlan tcpdump: WARNING: eth0: no IPv4 address assigned tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes On host machine we see that all is ok with traffic from node-17 root@anastasia-X9SRE-X9SRE-3F-X9SRi-X9SRi-3F:~# tcpdump -pnevvvvi vboxnet0 host 192.168.111.1 tcpdump: listening on vboxnet0, link-type EN10MB (Ethernet), capture size 65535 bytes 16:00:49.122187 fa:16:3e:b8:f7:86 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 46: vlan 1030, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.111.1 tell 192.168.111.2, length 28 16:00:50.123088 fa:16:3e:b8:f7:86 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 46: vlan 1030, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 192.168.111.1 tell 192.168.111.2, length 28 Looks like traffic does not go to node-15 at all host machine blocks this traffic This traffic is tagged by OpenVswitch if we create vlan network inrefaces on this nodes -- all is ok, traffic goes Hense we have the problem with tagged traffic fom OpenVswitch