6 Replies Latest reply on Jan 29, 2013 5:07 AM by Billy~Verreynne

    Enable IPV6 after installation

      Hi All,

      we have a oracle linux installation and currently a backup problem.
      We have debuged this issue and the problem is that our installation was done without the ipv6 option during the install guide.
      The backup agent need the IPV6 hardware adress.
      There are any possibility to enable the IPV6 support for oracle linux after the installation process?
      It's a production system and we can't reinstall the server ;)

        • 1. Re: Enable IPV6 after installation
          Please provide the following output:

          # cat /etc/issue
          # uname -r
          # ifconfig -a
          • 2. Re: Enable IPV6 after installation
            Cannot recall an option to only install IPv4 and not IPv6. The option is whether to use IPv6 or not. And that is set via +/etc/sysconfig/networking+.

            You can also use lsmod | grep  ipv6 to check for the module, and if the module is not loaded try modprobe ipv6. If this fails it likely means that you do not have the IPv6 kernel module installed.
            • 3. Re: Enable IPV6 after installation
              Had a look on a recently updated server of ours, and IPv6 is part of the kernel. It is not installed separately. E.g.
              // get kernel version
              [root@xxx ~]# uname -a
              Linux xxx 2.6.32-300.39.2.el5uek #1 SMP Wed Dec 19 14:56:59 PST 2012 x86_64 x86_64 x86_64 GNU/Linux
              // find package that contains IPv6 for this kernel via Public yum
              [root@xxx ~]# yum whatprovides '*/ipv6.ko' | grep 2.6.32-300.39.2.el5uek
              This system is not registered with ULN.
              You can use up2date --register to register.
              ULN support will be disabled.
              kernel-uek-2.6.32-300.39.2.el5uek.x86_64 : The Linux kernel
              Filename    : /lib/modules/2.6.32-300.39.2.el5uek/kernel/net/ipv6/ipv6.ko
              kernel-uek-debug-2.6.32-300.39.2.el5uek.x86_64 : The Linux kernel compiled with
              Filename    : /lib/modules/2.6.32-300.39.2.el5uek.debug/kernel/net/ipv6/ipv6.ko
              kernel-uek-2.6.32-300.39.2.el5uek.x86_64 : The Linux kernel
              Filename    : /lib/modules/2.6.32-300.39.2.el5uek/kernel/net/ipv6/ipv6.ko
              • 4. Re: Enable IPV6 after installation
                To expand a little on one point that Billy said:

                In /etc/sysconfig/networking

                Ensure the following is not set ( I suspect it is yes by default if this line is missing).


                For Persistent setup .....

                The utilities


                AFAIK should sort out the persistent configuration .... though I often seem to end up editting /etc/sysconfig/network-scripts/ifcfg-eth0 or whatever manually with ending up in a mess after using those utilties

                I think IPV6INIT=yes is necessary in the ifcfg-XXXXX file is necessary and to configure ipv6 perisistently for the interface.

                Possibly IPV6ADDR, IPV6_AUTOCONF and IPV6_MTU may be relevant in some situations.

                Probably definitive link (referenced in code on OL).


                Other Links:

                • 5. Re: Enable IPV6 after installation
                  Hi all,

                  here a colleague of Mathias..

                  We were able to enable IPV6 by removing the file /etc/modprobe.d/ipV6.conf which basically contained:
                  options ipv6 disable=1
                  alias net-pf-10 off
                  alias ipv6 off
                  install ipv6 /bin/true

                  After a reboot the kernel module was loaded and we automatically got IPV6 sockets.

                  Thank you all,
                  • 6. Re: Enable IPV6 after installation
                    Appreciate the resolution feedback. Not very often done and always useful for future readers looking at the same, or similar, problem,