Re: disabling ethernet loopback device completely

[Andrew Schulman <andrex@alumni.utexas.net>]

> 
>  Hi,
> 
>  I want to disable the loopback interface "lo" on my
> machine completely so that when I try to send data
> packets to the IP address that is configured for
> "eth0" on my local machine, the packets are actually
> put on the physical network.
> 
>  I've tried:
> 
>  ifdown lo
> 
> and while it disables the loopback interface, data
> packets are still not being put on the physical
> network. 

As a warning, don't be surprised if your machine slows to a crawl when 
you do this.  I once accidentally set the default policy to DROP in the 
iptables nat and mangle chains.  The loopback interface wouldn't pass 
any data, and my system became so slow it was almost unusable.  Once I 
restored loopback traffic things went back to normal.  Just FYI.