Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I know there is a parameter named ip which lets you configure IPv4 addresses on the Linux kernel through the boot loader. That looks like the following:

ip=192.0.2.1::192.0.2.62:255.255.255.192::eth0:none

I'm looking for an equal parameter for IPv6 configuration. I couldn't find anything about this in the kernel documentations.

Update: Because of a lot of you asked why I would need this: The idea to use a kernel configuration came up related to this problem. I suspect the regular boot-up interface configuration is not done, because the interfaces are already up. The reason for this could be that I'm using a pre-boot environment with a Dropbear SSH server to allow me to unlock my encrypted root partition. The IP addresses for this environment are configured through GRUB with the ip= parameter. There is no DHCP or Router Advertisement available on that Ethernet segment and as this is the uplink segment provided by a large hosting company, there is no way to change that fact.

share|improve this question
    
In fact, there isn't one. You can enable IPv6 autoconfiguration, but that is probably not what you are looking for. Is there a specific result you're trying to achieve (i.e. what is the reason you want to avoid IPv6 configuration in the machine's initialization process?) The ip= parameter was initially meant to configure the IP stack before the kernel tries to mount a NFS root filesystem, but I feel that you should rely on something else to achieve the same result with IPv6 (most probably, SLAAC). –  pino42 Nov 4 '12 at 16:08
    
I know about SLAAC. But I need to set it up manually. –  aef Nov 4 '12 at 17:57
2  
My feeling is that since the introduction of the "early userspace" feature (initramfs either embedded in the kernel or as a separate file like traditional initrd), you are encouraged to do such things as configuring IP addresses there instead of with special one-off command line parameters. That's probably why there is a historical command line parameter for IPv4 but none was added for IPv6. –  Celada Nov 4 '12 at 19:19
    
At what time in the boot process do you need it to be set? –  pino42 Nov 5 '12 at 9:17
    
It's extremely unlikely that you need this. What exactly are you trying to accomplish? –  Michael Hampton Nov 15 '12 at 16:26

2 Answers 2

up vote 2 down vote accepted

Sorry, but if you want this, you'll have to build it yourself, or more likely, reuse someone else's implementation.

The ip= command line option you've been using is actually part of the kernel's boot code for mounting an NFS root filesystem. It has never been extended for IPv6, and there is no kernel boot parameter for configuring IPv6 at boot time.

That said, some Linux distributions such as Red Hat have implemented their own ipv6= boot parameter for their installation media. You may be able to reuse this code in your custom initramfs.

share|improve this answer

All your boot parameters are available via /proc/cmdline after boot. So, you can just set up all needed options via custom mkinitcpio hook, which would parse cmdline in search for specific param. You can use ipv6= like ip= one.

share|improve this answer
    
Yeah. I could build it myself, but that was not what I'm looking for. Still thanks for the idea. –  aef Nov 16 '12 at 16:11

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.