Disabling IPv6 on *one* network interface in Debian

[Frank Bulk]

That did the trick Brandon, many thanks!  I still have a link-local address,
but the GUA is gone.

Frank

-----Original Message-----
From: Brandon Applegate [mailto:brandon at burn.net] 
Sent: Friday, February 04, 2011 12:03 AM
To: Frank Bulk
Cc: 'Martin Millnert'; ipv6-ops at lists.cluenet.de;
ipv6-techsig at mailman.internetnz.net.nz
Subject: RE: Disabling IPv6 on *one* network interface in Debian

On Thu, 3 Feb 2011, Frank Bulk wrote:

> I tried that, no luck.
> ===================================
> iface eth0.100 inet static
>       pre-up sysctl -w net.ipv6.conf.eth0/100.autoconf=0
>       pre-up sysctl -w net.ipv6.conf.eth0/100.accept_ra=0
>       address a.b.c.d
>       netmask 255.255.255.0
>       network a.b.c.0
> ===================================
>
> Results in
>   error: "net.ipv6.conf.eth0.100.autoconf" is an unknown key
>
> Of course, once the interface is up, I can execute sysctl manually. To
change the autoconf and accept_ra.
>   root at nagios:/etc/network#  sysctl -w net.ipv6.conf.eth0/100.autoconf=0
>   net.ipv6.conf.eth0/100.autoconf = 0
>   root at nagios:/etc/network#  sysctl -w net.ipv6.conf.eth0/100.autoconf=0
>   net.ipv6.conf.eth0/100.autoconf = 0
>   root at nagios:/etc/network#
>
> Frank


I'm *thinking* it's a race condition.  Debian is going to create that 
interface on demand with vconfig.  So I think pre-up is trying to run and 
the interface isn't created yet.  This is messy, but what about:

post-up ifconfig eth0.100 down
post-up sysctl -w net.ipv6.conf.eth0/100.autoconf=0 
post-up sysctl -w net.ipv6.conf.eth0/100.accept_ra=0
post-up ifconfig eth0.100 up