We have a lot of nodes with centos 6 + Openvz (solusvm slave) and in all old nodes IPv6 is working inside containers without any problems. Now we installed new centos 6 + openvz (solusvm slave) slave node server with the same network configuration as in our old nodes, but in this newest node Ipv6 inside containers not working. Had tryed alot of configurations etc but nothing helps... Signs and details of this problem: 1) Node can ping external Ipv6 address, so Ipv6 in the node itself is working. 2) Node can ping local container Ipv6 address 3) Container can ping node ipv6 address 4) Container cannot ping external ipv6 address One of the difference sign in this newest node is when we restarting networking in the node with the command: service network restart. It shows some errors (changed some IPs details to AAAA:BBB:CCC): Shutting down interface eth0: [ OK ] Shutting down interface venet0: Shutting down interface venet0: [ OK ] Shutting down loopback interface: [ OK ] Bringing up loopback interface: [ OK ] Bringing up interface eth0: RTNETLINK answers: Invalid argument ndsend: Error in sendto(): Cannot assign requested address ifup-local WARNING: arpsend -c 1 -w 1 -U -i AAAA:BBB:CCC:4208:0:0:0:3 -e AAAA:BBB:CCC:4208:0:0:0:3 eth0 FAILED [ OK ] Bringing up interface venet0: Bringing up interface venet0: Configuring interface venet0: net.ipv4.conf.venet0.send_redirects = 0 Configuring ipv6 venet0: ndsend: Error in sendto(): Cannot assign requested address ifup-venet WARNING: arpsend -c 1 -w 1 -U -i AAAA:BBB:CCC:4208:0:0:0:3 -e AAAA:BBB:CCC:4208:0:0:0:3 eth0 FAILED [ OK ] So, this error may be related to our problem: ndsend: Error in sendto(): Cannot assign requested address ifup-local WARNING: arpsend -c 1 -w 1 -U -i AAAA:BBB:CCC:4208:0:0:0:3 -e AAAA:BBB:CCC:4208:0:0:0:3 eth0 FAILED We have contacted data center stuff regarding this problem, but they replyied that everything is working normally from their side (IPv6 is working in the node itself). IPv6 /64 subnet (changed) assigned to node: AAAA:BBBB:CCCC:4208::/64 Node IP (changed): AAAA:BBBB:CCCC:4208::2 Container IP (changed): AAAA:BBBB:CCCC:4208::3 Gateway: fe80::1 # cat /etc/sysctl.conf net.ipv4.icmp_echo_ignore_broadcasts=1 net.ipv4.ip_forward = 1 kernel.sysrq = 1 net.ipv4.conf.default.proxy_arp = 0 net.ipv4.conf.all.rp_filter = 1 net.ipv4.conf.default.send_redirects = 1 net.ipv4.conf.all.send_redirects = 0 net.ipv6.conf.default.forwarding = 1 net.ipv6.conf.all.forwarding = 1 net.ipv6.conf.default.proxy_ndp = 1 net.ipv6.conf.all.proxy_ndp = 1 # cat /etc/sysconfig/network # general networking NETWORKING=yes HOSTNAME=server.domain.com # cat /etc/sysconfig/network-scripts/ifcfg-eth0 # device: eth0 DEVICE=eth0 BOOTPROTO=static BROADCAST=x.x.x.x HWADDR=x:x:x:x:x:x IPADDR=y.y.y.y NETMASK=255.255.255.255 SCOPE="peer x.x.x.x" IPV6INIT=yes IPV6ADDR=AAAA:BBBB:CCCC:4208::2 IPV6_DEFAULTGW=fe80::1 IPV6_DEFAULTDEV=eth0 # cat /etc/sysconfig/network-scripts/route6-eth0 fe80::1 dev eth0 ::/0 via fe80::1 # ip -6 route list unreachable ::/96 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 unreachable ::ffff:0.0.0.0/96 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 unreachable 2002:a00::/24 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 unreachable 2002:7f00::/24 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 unreachable 2002:a9fe::/32 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 unreachable 2002:ac10::/28 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 unreachable 2002:c0a8::/32 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 unreachable 2002:e000::/19 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 AAAA:BBBB:CCCC:4208::3 dev venet0 metric 1024 mtu 1500 advmss 1440 hoplimit 4294967295 AAAA:BBBB:CCCC:4208::/64 dev eth0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 unreachable 3ffe:ffff::/32 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295 fe80::1 dev venet0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 fe80::1 dev eth0 metric 1024 mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev eth0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev venet0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 default via fe80::1 dev eth0 metric 1 mtu 1500 advmss 1440 hoplimit 4294967295 Maybe someone else experienced this kind of problem or know solution? Thank you very much for any reply, help or advise regarding this issue.
UPDATE to this problem: 1) IPv6 inside container starting to work if execute ping6 to the real gateway/router address (not fe80::1). After that IPv6 inside container in which ping to real gateway/router IPv6 address executed started to work! 2) Maybe this error is also releated to our problem. Executing this command in node with IPv6 problem we receiving error: root@server ~]# ip -6 neigh fe80::1 dev eth0 router FAILED If we execute this command in the node where IPv6 is working normally there is no error: [root@server ~]# ip -6 neigh fe80::1 dev eth0 lladdr 78:de:cc:34:fa:95 router STALE Is anyone experienced this issues and know how to fix this permanently without ping to router execution? Thank you for any help.