Hello! After about 10 minutes of inactivity, the Internet can no longer communicate with my server's IPv6 IP address, and I'm not sure why.
When I set up the tunnel broker using CentOS 6.2 and the sit0/sit1 method, and do a "/etc/init.d/network restart", everything comes up beautifully. I can ping out and connect to IPv6 hosts, and hosts can do the same inbound to me.
After about 10 minutes of inactivity, hosts can no longer ping inbound, and can no longer access other inbound resources like ssh and http. It's as if the tunnel is down.
On the server though, if I ping outbound IPv6 to anywhere, it brings the tunnel back to life and the world can ping and access inbound services.
I heard that IPv6 relies on icmp to determine if an IP is online, so I ensured icmpv6 is enabled inbound:
iptables -I INPUT -p icmpv6 -j ACCEPT
Still no help. The problem temporarilly goes away if I log in the to the server and do a
ping6 ipv6.any-host-on-the-internet
Then other hosts will see my IPv6 address as up, at least for a few minutes.
Anyone have any ideas? I'd rather not set up a cron to do an icmp ipv6 ping outbound every minute, unless it's a last resort, but I'd rather fix the problem than just apply some duct tape to it.
Below are my configs. For security reasons, I changed some of the below ipv4 and ipv6 addresses, so these IPs are not the actual ones i'm working with.
/etc/sysconfig/network:
NETWORKING=yes
HOSTNAME=my.host.com
GATEWAY=209.100.1.1
NETWORKING_IPV6=yes
IPV6_AUTOTUNNEL=yes
IPV6FORWARDING=yes
IPV6_AUTOCONF=no
/etc/sysconfig/network-scripts/ifcfg-eth0:
DEVICE=eth0
BOOTPROTO=static
BROADCAST=209.100.1.7
GATEWAY=209.100.1.1
HWADDR=00:25:90:56:10:35
IPADDR=209.100.1.2
IPV6INIT=yes
IPV6_AUTOCONF=no
NETMASK=255.255.255.248
NM_CONTROLLED=no
ONBOOT=yes
/etc/sysconfig/network-scripts/ifcfg-sit1:
TYPE=sit
DEVICETYPE=sit
ONBOOT=yes
DEVICE=sit1
BOOTPROTO=none
IPV6INIT=yes
IPV6ADDR=2001:470:1f:d2::2/64
IPV6TUNNELIPV4=216.218.224.42
IPV6TUNNELIPV4LOCAL=209.100.1.2
IPV6ADDR_SECONDARIES="2001:470:1f:d2:4e66:84d4:d1d7:fd38/64"
/etc/sysconfig/network-scripts/route6-sit1:
::/0 dev sit1
Output of "ifconfig -a":
eth0 Link encap:Ethernet HWaddr 00:25:90:56:10:35
inet addr:209.100.1.2 Bcast:209.100.1.7 Mask:255.255.255.248
inet6 addr: fe80::225:90ff:fe56:1035/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:138398008 errors:0 dropped:0 overruns:0 frame:0
TX packets:213651810 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:65616826953 (61.1 GiB) TX bytes:295239216577 (274.9 GiB)
Interrupt:16 Memory:fba00000-fba20000
eth0:1_3 Link encap:Ethernet HWaddr 00:25:90:56:10:35
inet addr:209.100.1.3 Bcast:209.100.1.7 Mask:255.255.255.248
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:16 Memory:fba00000-fba20000
eth1 Link encap:Ethernet HWaddr 00:25:90:56:10:36
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:18 Memory:fb900000-fb920000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:10915 errors:0 dropped:0 overruns:0 frame:0
TX packets:10915 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:100624590 (95.9 MiB) TX bytes:100624590 (95.9 MiB)
sit0 Link encap:IPv6-in-IPv4
inet6 addr: ::127.0.0.1/96 Scope:Unknown
inet6 addr: ::209.100.1.2/96 Scope:Compat
inet6 addr: ::209.100.1.3/96 Scope:Compat
UP RUNNING NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:5 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
sit1 Link encap:IPv6-in-IPv4
inet6 addr: 2001:470:1f:d2:4e66:84d4:d1d7:fd38/64 Scope:Global
inet6 addr: 2001:470:1f:d2::2/64 Scope:Global
inet6 addr: fe80::d169:f202/128 Scope:Link
UP POINTOPOINT RUNNING NOARP MTU:1480 Metric:1
RX packets:18 errors:0 dropped:0 overruns:0 frame:0
TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1872 (1.8 KiB) TX bytes:1872 (1.8 KiB)
And output of "ip -6 route" does show default route over device sit1:
2001:470:1f:d2::/64 via :: dev sit1 proto kernel metric 256 mtu 1480 advmss 1420 hoplimit 4294967295
default dev sit1 metric 1024 mtu 1480 advmss 1420 hoplimit 4294967295
Most likely your providers router does not provide a fully working inbound mapping of IP protocol 41 (6to4). I've got the exact same problem, only the Thomson TG587n V2 provided by my ISP (O2 Broadband) times out after a 1 minute.