Subject: Re: Do you know the TCP stack? (127.x.x.x routing)

From: Andi Kleen <[email-masked]>
Date: 6 Mar 2005 22:30:47 +0100

On Sun, Mar 06, 2005 at 09:45:16PM +0100, Thomas Graf wrote:
> * Andi Kleen <[email-masked]> 2005-03-06 21:19
> > Zdenek Radouch <[email-masked]> writes:
> > >
> > > There is no doubt that the 127.x net is treated in a special
> > > way.  If I have to believe what I just learned, then the 127
> > 
> > It is. 127.* is hardcoded in the routing engine and e.g.
> > it won't accept outside packets with a loopback address.
> > 
> > Most likely it's enough to change the "LOOPBACK" macro to allow
> > parts of the Class A to be used for other purposes.
> 
> Yes, it will work around the martian route and arp checks but
> will probably break quite a few usersapce applications.

Unlikely. glibc has an own LOOPBACK() and all modern distributions
use separate kernel/user headers anyways.

-Andi