31 May

IPv4 and IPv6

Here are some pages on which you can get information about IPv6:

  • http://en.wikipedia.org/wiki/IPv6
  • http://www.olympus-zone.net/page_1033_en_Blue.html
  • IPv6 at Xoftmade

    For our facilities, we have the following /32 Netz: 2001:41D0::/32

    For the routing we use Cisco routers 6k (6509 SUP720 card with the native IPv6 packets to route).

    Every customer with a dedicated server at Xoftmade has a fixed IPv4, one or more IpFailover and 18,446,744,073,709,551,616 IPv6 addresses (ie a /64) are attached to the IPv4 server.

    So you can with a dedicated server:

    • Use multiple SSL certificates
    • Several anonymous FTP operations
    • Web-hosting service run (IP-based)
    • A public VPN set up based on the dedicated server
    • Etc. ..


    • The server must be running with a IPv6 kernel. This kernel is available by netboot Netboot
    • Find your own IPv6 address in manager v3 Manager

    An IPv6 example
    An IPv4:

    IPv6 will be the following:


    Here are examples from which you can configure IPv6 on your dedicated server:


    The following notations are the same:


    But you can :: place only once.

    An example ifconfig
    Once you’ve switched the server to IPv6 kernel, after the reboot ifconfig already has IPv6 info:

    adr inet6: fe80::2e0:4cff:fe99:88d0/64 Scope:Lien

    This shows that IPv6 works on the network.Route: IPv6 Gateway

    The router (default gateway) for each IPv6 is always on IP: v:6:FF:FF:FF:FF:FF

    For example:

    The IPv6 server: 2001:41D0:1:46e::/64 to 2001:41D0:1:4 + 5x FF.
    IPv6 Gateway: 2001:41D0:1:4FF:FF:FF:FF:FF

    The IPv6 server: 2001:41d0:1:209::/64 to 2001:41d0:1:2 + 5x FF.
    IPv6 Gateway: 2001:41d0:1:2FF:FF:FF:FF:FF

    IPv6 Installation

    To be used for all Linux distributions in the examples below, the server has IPv6, the IPv6 kernel and it is has the address from the manager. A uname-a indicates that an IPv6 kernel, and the command shows us that ifconfig The Router IPv6 already have a local link.

    Redhat, CentOS, Fedora

    The dedicated server we are running configure with the IPv4:, this will lead to the following IPv6: 2001:41d0:1:209::/64.
    The following examples are identical for Redhat 7.2, Fedora and CentOS. You can therefore also use it for Xoftmade Release Plesk, (based on CentOS).

    eth0 Lien encap:Ethernet HWaddr 00:E0:4C:99:88:D0
    inet adr: Bcast: Masque:
    adr inet6: fe80::2e0:4cff:fe99:88d0/64 Scope:Lien

    We do 2001:41D0:1:209::1/64 and 2001:41D0:1:209::5/64 Add to eth0 :

    /sbin/ifconfig eth0 inet6 add 2001:41D0:1:209::1/64
    /sbin/ifconfig eth0 inet6 add 2001:41D0:1:209::5/64

    So IPv6 does not disappear at the next reboot it must be added in the configuration file of the eth0 interface. We will create a copy of the file and then edit it:

    cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth.backup
    pico /etc/sysconfig/network-scripts/ifcfg-eth0

    Here are the contents of the file after the change. The red options were added:


    All of the following IPv6 must be located in the line IPV6ADDR_SECONDARIES
    It has the file /etc/sysconfig/network edited this line and add NETWORKING_IPV6=yes

    # This line commented out by System Configuration

    It must be restarted with /etc/init.d/network restart
    Note: It is possible that Redhat displays an error: “modprobe: Can not open dependencies file …” You can ignore this, it does not affect the result.

    ifconfig ?

    eth0 Lien encap:Ethernet HWaddr 00:E0:4C:99:88:D0
    inet adr: Bcast: Masque:
    adr inet6: 2001:41d0:1:209::1/64 Scope:Global
    adr inet6: 2001:41d0:1:209::5/64 Scope:Global
    adr inet6: fe80::2e0:4cff:fe99:88d0/64 Scope:Lien

    You may be able to ping the gateway but can not use your ipv6, in this case add a default route:

    route -A inet6 add default gw votre.gateway.ipv6 dev eth0

    For example:

    route -A inet6 add default gw 2001:41d0:1:2FF:FF:FF:FF:FF dev eth0


    Ping6 Test

    We ping6 to the router:

    ping6 -c 4 2001:41d0:1:2FF:FF:FF:FF:FF
    PING 2001:41d0:1:2FF:FF:FF:FF:FF(2001:41d0:1:2ff:ff:ff:ff:ff) from 2001:41d0:1:209::5 : 56 data bytes
    64 bytes from 2001:41d0:1:2ff:ff:ff:ff:ff: icmp_seq=0 hops=64 time=127.977 msec
    64 bytes from 2001:41d0:1:2ff:ff:ff:ff:ff: icmp_seq=1 hops=64 time=24.242 msec
    64 bytes from 2001:41d0:1:2ff:ff:ff:ff:ff: icmp_seq=2 hops=64 time=205.934 msec
    64 bytes from 2001:41d0:1:2ff:ff:ff:ff:ff: icmp_seq=3 hops=64 time=129.853 msec

    4 packets transmitted, 4 packets received, 0% packet loss
    round-trip min/avg/max/mdev = 24.242/122.001/205.934/64.613 ms

    Traceroute6 Test

    Do traceroute6 to IPv6 DNS Servers by Afnic:

    traceroute6 2001:660:3006:1::1:1
    traceroute to 2001:660:3006:1

    1:1 (2001:660:3006:1

    1:1) from 2001:41d0:1:209::5, 30 hops max, 16 byte packets
    1 2001:41d0:1:2ff:ff:ff:ff:ff (2001:41d0:1:2ff:ff:ff:ff:ff) 0.726 ms 0.508 ms *
    2 * * *
    3 renater.sfinx.tm.fr (2001:660:a100:2::1) 0.879 ms 0.787 ms 0.721 ms
    4 afnic.sfinx.tm.fr (2001:660:a100:2::101) 1.13 ms 1.131 ms 1.099 ms
    5 ns3.nic.fr (2001:660:3006:1::1:1) 0.933 ms 0.954 ms 0.922 ms

    It is working.
    There are websites that can offer a traceroute6 ping6 or tests online. You can use these function to check with the added IPs.

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