IPv6 Day - Setup IPv6 at Hetzner.de
This will give them a good way to see if there's still anything buggy in their setups but is also meant as an encouragement for everybody to finally make the switch to IPv6.
Now the servers running DokuWiki.org and splitbrain.org are native IPv6 enabled, too.
Both servers are hosted at Hetzner. Since this is a popular provider in Germany I thought it might be a good idea to give a short introduction on what I had to do to make my servers IPv6 enabled.
You will need a IPv6 capable firewall script. Unfortunately these seem still to be rare. On splitbrain.org I'm using Arno's Firewall Script. Unfortunately a recent version with proper IPv4 and IPv6 support is only available in testing. But you can simply install the package from testing:
#> wget http://ftp.de.debian.org/debian/pool/main/a/arno-iptables-firewall/arno-iptables-firewall_2.0.0.a-2_all.deb #> dpkg -i arno-iptables-firewall_2.0.0.a-2_all.deb
All you need to do for IPv6 support is set the follwing option in
On the DokuWiki.org server we're running shorewall. For IPv6 support you'll need to install the shorewall6 package on Debian and setup a completely new firewall right beside to your IPv4 one. Luckily you can simply copy (or even symlink) most config files as they work exactly the same as for IPv4.
Next, is to configure the IP address. Hetzner has native IPv6 support so there's no need to fiddle with any tunnel configs. They provide you with your own IPv6 /64 subnet, just order in the robot. A minute later you'll get a mail with the details.
Here's what I got for the splitbrain.org server:
IPs: 2a01:4f8:140:5484:: /64 Gateway: 2a01:4f8:140:5480::1 /59 Usable IP-Adresses: 2a01:4f8:140:5484::2 bis 2a01:4f8:140:5484:ffff:ffff:ffff:ffff
Since there's no router advertisement, IPs have to be set statically.
As you can see, the gateway is not part of the subnet you got assigned. Hetzner's wiki recommends to set a route to the gateway. That worked well on the command line but didn't work when put in the
/etc/network/interfaces config of my Debian system1). This was probably caused by a bug in Arno's Firewall.
My workaround was to simply set up my interface with the full /59 network. This way, the route to the gateway is implicitly clear. Of course I have to remember not to use any addresses outside my real /64 address range, but I don't plan to use more than one address anyway.
This is what my setup looks like now:
# Loopback device: auto lo iface lo inet loopback # device: eth0 auto eth0 # IPv4 Configuration iface eth0 inet static address 18.104.22.168 broadcast 22.214.171.124 netmask 255.255.255.224 gateway 126.96.36.199 post-up mii-tool -F 100baseTx-FD eth0 # default route to access subnet up route add -net 188.8.131.52 netmask 255.255.255.224 gw 184.108.40.206 eth0 # IPv6 Configuration iface eth0 inet6 static address 2a01:4f8:140:5484::b00b netmask 59 gateway 2a01:4f8:140:5480::1
After a reboot, you should check if your interface has the correct IP:
# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:21:85:63:78:18 inet addr:220.127.116.11 Bcast:18.104.22.168 Mask:255.255.255.224 inet6 addr: 2a01:4f8:140:5484::b00b/59 Scope:Global inet6 addr: fe80::221:85ff:fe63:7818/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:47441 errors:0 dropped:0 overruns:0 frame:0 TX packets:71811 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:7504499 (7.1 MiB) TX bytes:89090259 (84.9 MiB) Interrupt:25 Base address:0x2000
Looks good. Let's check for the default gateway:
# ip -f inet6 route 2a01:4f8:140:5480::/59 dev eth0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev eth0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 4294967295 default via 2a01:4f8:140:5480::1 dev eth0 metric 1 mtu 1500 advmss 1440 hoplimit 4294967295
Good as well. Let's ping the gateway:
$ ping6 2a01:4f8:140:5480::1 PING 2a01:4f8:140:5480::1(2a01:4f8:140:5480::1) 56 data bytes 64 bytes from 2a01:4f8:140:5480::1: icmp_seq=1 ttl=64 time=4.46 ms
Now let's ping something outside, we can use the IP of heise.de:
$ ping6 2a02:2e0:3fe:100::8 PING 2a02:2e0:3fe:100::8(2a02:2e0:3fe:100::8) 56 data bytes 64 bytes from 2a02:2e0:3fe:100::8: icmp_seq=1 ttl=56 time=19.4 ms
The same again with DNS name:
$ ping6 heise.de PING heise.de(redirector.heise.de) 56 data bytes 64 bytes from redirector.heise.de: icmp_seq=1 ttl=56 time=19.4 ms
Finally ping the server from the outside2):
$ ping6 2a01:4f8:140:5484::b00b PING 2a01:4f8:140:5484::b00b(2a01:4f8:140:5484::b00b) 56 data bytes 64 bytes from 2a01:4f8:140:5484::b00b: icmp_seq=1 ttl=52 time=56.9 ms
Once everything works, you need to add AAAA records in your DNS to point your domains to the IPv6 address as well.
I manage my domains through regfish, where I have a convenient web interface for adding DNS setups.
You should also add a reverse DNS entry for the IP you configured at your server. This has to be done whereever you got the domains from. In my case at Hetzner's robot:
ip routecalls in the
upstanzas seemed to be igonored