Hope you stay with me on this one

In a small network with 3 laptops, one desktop and one server (all Slackware 10.2) and a Linksys GW running openwrt (Linux), we want to achieve full mobility: All users should be able to log in on any laptop/server and find their home environment, files etc. Currently this is solved with NFS and the home area mounted from the server. Thus any user can login from any computer and find himself at home.

However: Once I bring a laptop out of the apartment, I no longer have access to any of my files or settings, and cannot even log in.

Thus I figure every user stores his/her files on his/her laptop, share this with NFS and set up automount. So far so good.
I now can login from any computer, and all personal files are stored on the personal laptop of the user, shared with NFS+automount.

Finally, we want full mobility with wireless+wired networking. This is achieved through ifupd. If a laptop has access to a wired network, it will be used for performance reasons, but once the wired interface is unplugged, the system immediately, without any delay, swaps over to WLAN.

The PROBLEM: This wlan/wired dual connectivity causes the PC to have two IP addresses on the local network. This in turn causes the laptop to get two names on the system, for instance asterix-1 and asterix-2, one for each interface card. However, this breaks the NFS automount.

Solution??: Is there any way to get the active network connection, the one with the preferable routing metric set by ifplugd, to update the DNS server on the gateway (running dnsmasq) with the correct IP address, so that DNS name asterix always points to the ACTIVE IP address with the preferred bandwidth available?

Or are there any other solutions to ensure that :

1. All users can use any laptop/machine and get their home environment
2. Home files stored on primary laptop, shared with NFS and autmount of /home
3. Always on connectivity at home when moving from wired to wireless

We can ofcourse live with a second or two transmission loss during change of media (ie when unplugging wired cable) as most TCP applications don't fail on this one, and I assume NFS will have to re-sync, but apart from that, the moving freely around should not be hindered.

I am looking forward to a lively discussion on this one!

-Y1

Can't help with metrics/ifplug and having a machine name for each interface.
Took a different route in achieving mobility you might look at.

On the usera own laptop/workstation he is created and has a HOME of /home/usera.
On a server he is created with the same UID with a HOME of /home/users/usera

The passwd file on each machine is edited with respect to appropriate HOME or use NIS and only add the owner to the passwd file and let +:::::: permit other users to login (if HOME is found on the server).

The problem is to sync the two home directories. The approach I used was to use .bash_login(out) script which would check if the HOME was /home/usera if so copy new files from the server on login and delete files on the server and copy new files to the server on logout. If HOME is /home/users/usera the script does nothing. This requires use of init 3 on boot.

Now a user can login on userb laptop even if his(a) laptop is in the car (and off). Since the automount entry is to the fixed named server it should not matter which interface is being used (ASSUMPTION on my part).
Hope this helped.