Getting IPv6 working with SmartOS and KVM
Just about 2 weeks ago I started to play around with SmartOS.
SmartOS is a fairly recent hypervisor for virtualization, open-sourced by Joyent, the great guys behind node.js in August 2011. It's based on Illumos, which itself is a fork of Solaris.
The wiki is a great place to get started as well as the man page for vmadm. Of course I found more articles and saved them in my pinboard account.
But one thing I did not really get to work was IPv6. After a while I found the wiki page for IPv6 in a zone which worked, atleast for SmartOS zones.
But I had no luck with my KVM-based Ubuntu machine. I did it the same way,
using basic tools (
/etc/network/interfaces), but I could not
even ping the machine itself from within the page.
So I asked in the IRC channel (#smartos on freenode, great and friendly guys ;))
While IPv6-support is still not included in SmartOS tools itself some patches for this exist.
This is only for zones and not for KVM instances, but I was told to check
dmesg and other logs (d'oh! Why didn't I do this before?)
And this is what I found:
eth0: IPv6 duplicate address detected!
A quick search turned up a forum post which linked to this blog post.
sudo sysctl net.ipv6.conf.eth0.accept_dad=0
/etc/sysctl.conf to make it persistent.
This disables the Duplicate Address Detection.
After a reboot everything works and the machine works over IPv6.
When I talked to Eimann about this he directly knew another related problem and the explanation:
If you're wondering why a Linux machine won't do v6 anymore when doing a (Cisco SPAN) monitor session over a VLAN which also hosts the default network: The machine sees some Neighbor-talking over the VLAN and switches to
dadfailedeffectively breaking the v6.