Subject: Re: [RFC] ipv6: use a random ifid for headerless devices

From: Bjørn Mork <[email-masked]>
Date: Thu, 03 Dec 2015 20:29:53 +0100

Hannes Frederic Sowa <[email-masked]> writes:

> I see no problem with the patch as it eases operating those devices. I
> would also suggest storing the ifid in the inet6_dev so it does only
> change during device creation and destruction. Otherwise I would
> recommend to use stable privacy addresses to generate the link local
> addresses. EUI-48 based LL creation should hopefully not be used anymore
> soon.

Thanks for commenting on this. Yes, the stable privacy addresses looks
like they will solve this and other problems.  But enabling them require
an adminstrator action.

After looking more at addrconf, I started wondering if we couldn't abuse
ipv6_generate_stable_address() for this purpose?  We could add a new
addr_gen_mode which would trigger automatic generation of a secret if
stable_secret is uninitialized.  This would be good enough to ensure
stability until the interface is destroyed.  And it would still allow
the adminstrator to select IN6_ADDR_GEN_MODE_STABLE_PRIVACY by entering
a new secret.

Bjørn