Online.net IPv6 Setup (with reverses!)

IPv6-LogoLet’s skip the lengthly introduction and get right into it: In this article, I’ll cover how to set up IPv6 connectivity to your online.net dedi, and how to set up reverse DNS records. If you want reverse DNS records (which you want if you’re hosting email), you’ll need to be running your own authoritative DNS server, which I won’t be covering here. As far as I know, there’s no way to get a PTR record for your address without running your own server.

Online.net console

  1. Log in to your online.net console, and head over to Server > Network configuration.
  2. Order your IPv6 block. In a while, you’ll get a /48. Took about half an hour for me. When it’s ready, it’ll appear in the list with Done appearing in the Delegation Status column.
  3. Click the gear beside your delegation > Edit nameserver delegation. You will have to specify two nameservers. If you only have a single authoritative server, you can use a backup server service, like the one provided on afraid.org.
  4. Once finished, click the gear beside your /48 delegation again > Create subnet. This will create a /56, which you’ll assign to your server. Pick one you like. You can create as many subnets as you have servers.
  5. Note the address and DUID of your /56. That’s all we need from the console.

Your server

On your server, we’ll set up dhclient and configure your interfaces.

  1. Edit /etc/network/interfaces. Append the following:
    iface eth0 inet6 static
    #this enables ipv6 on eth0, and sets a static address
    address 2001:bbbb:cccc:100::1
    #replace the above with your /56 delegation, but make sure
    #it ends with ::1 (or whatever other number you want)
    netmask 56
    #specifies the netmask
    accept_ra 1
    #accepts router advertisements, you need this
    pre-up /sbin/dhclient -1 -v -pf /run/dhclient6.eth0.pid -lf /var/lib/dhcp/dhclient6.eth0.leases -cf /etc/dhcp/dhclient6.conf -6 -P eth
    #this will feed /etc/dhcp/dhclient6.conf (which we still have yet
    #to create) to dhclient when the interfaces are being loaded
  2. Create /etc/dhcp/dhclient6.conf, containing:
    interface "eth0" {
    send dhcp6.client-id 00:03:00:01:7a:c6:00:11:22:33;
    #replace above line with your DUID for you /56
    #don't forget the semicolon!
    request;
    }
  3. Reboot, or systemctl restart networking.

Reverse DNS

Very similar to how IPv4 PTR records work.

  1. Create a zone file for your /48. The zone file name will be the first three quartets, reversed, character separated by periods, followed by ip6.arpa. So for me, if I was assigned 2001:bbbb:cccc::, I’d go with c.c.c.c.b.b.b.b.1.0.0.2.ip6.arpa.
  2. Create the zone file as usual, with an IN PTR record for your server’s address (the one that ends with :1). This tool makes life easy for reversing the entire address.

Firewall

You need to allow through UDP port 546,547 for DHCP to work out.

That’s it! Remember to set up ip6tables or whatever firewall you prefer. Happy IPv6-ing!

2 thoughts on “Online.net IPv6 Setup (with reverses!)”

  1. Hi,

    I’m not sure where to put that PTR record. Should I delegate ipv6 to my own dedibox server at online.net? Currently I’ve put domain servers from GoDaddy DNS service which I’m using, but also can’t setup that PTR there… Could you please explain that ipv6 revdns a little more?

    1. As mentioned in the introduction, “If you want reverse DNS records (which you want if you’re hosting email), you’ll need to be running your own authoritative DNS server, which I won’t be covering here. As far as I know, there’s no way to get a PTR record for your address without running your own server.”

Leave a Reply

Your email address will not be published.