Re: Networking Q concerning /etc/network/interfaces
the interfaces file is really only going to come into pay during
bootup, or when using eg ifup/ifdown scripts.
You indicated that you may have configured the interfaces by hand via
ifconfig; if so those changes will not survive a reboot. How long
since your last reboot?
If it's safe to do on this machine, I would try to reboot it and see
if it comes up with the settings in your interface file this time.
Also, in case this is a remote host or a production machine be
prepared to intervene with direct terminal access on the off chance it
stubbornly refuses to be connectable on bootup.
If the anomaly survives a reboot, I would next use the following
command to see what if any software or scripts are configured to muss
around with the interfaces:
grep -r 'eth' /etc
- - Jesse