On 5/06/2014 7:39 AM, 神明達哉 wrote:
Disabling DAD on that interface certainly looks too much if the purpose is to allow node-local communication using a "detached" address. One possibility would be to introduce a tweakable switch that disables the DNA operation at the risk of allowing the small window on link up. Another, probably more substantial but probably cleaner change would be to allow using a detached address for (node) local communication (e.g., allow bind() but filter out packets using a detached address if they are sent to the wire rather than loopback).
All of these suggestions have merit as I'm also of a mind to not disable (or need to disable) DAD just to support node-local communication whilst the link is down.
I've not tested this, but wouldn't a host route to the interface address via the loopback address work?Is this a question of whether local communication using a detached address is currently possible? I don't fully remember either, but the host route itself should work (unless it's removed as a result of the status change to detached). But there may be other issues, like whether bind(2) is allowed for that address.
Yes - part of the problem here is that bind(2) currently fails and I cannot see how creating a host route would fix that. Darren