Re: REQUEST: Network Interface Failover and multi-DNS resolution

[Aaron Bennett <aaron bennett olin edu>]

Carlos Rodrigues wrote:

> I don't think this is only a router thing. What I'm talking about is 
> just what I mentioned above. Keep the DHCP info for all interfaces, 
> change resolv.conf et al with the data from the first interface. If 
> that interface *link* goes down (cable unplugged), just pick the data 
> from the next interface and apply it. The first one is always the 
> boss, if its link goes up, its settings get reapplied.
> I don't think this is anything esoteric, we already have something 
> keeping an eye on the interface, otherwise we would get no DHCP 
> request when the link comes back up. It just has to be changed so that 
> the whatever daemon that is monitoring the interface that we consider 
> the primary applies the settings for the next interface when it sees 
> its interface going down.
>
> Note that I'm not talking about the default gateway going down or some 
> failure like that. That's the reason I brought the wireless scenario. 
> The fact is our windows users can unplug their laptops from the wired 
> LAN (the "staff" network) and move around the building without having 
> to restart their network interfaces (the wireless network is part of 
> the "students" LAN, a wide-open insecure separate LAN). Our Linux 
> users can't.

We use the combination of ifplugd & waproamd 
(http://www.stud.uni-hamburg.de/users/lennart/projects/) to make Linux 
wireless not suck.  Check them out.



--
Aaron Bennett
UNIX Administrator
Franklin W. Olin College of Engineering