Re: /etc/init.d/networking does not start everything in /etc/network/interfaces

[Brian <ad44@cityscape.co.uk>]

On Wed 18 May 2016 at 12:32:24 -0500, David Wright wrote:

> On Wed 18 May 2016 at 17:39:45 (+0100), Brian wrote:
> > On Wed 18 May 2016 at 10:44:40 -0500, David Wright wrote:
> > 
> > > On Wed 18 May 2016 at 10:56:01 (-0400), Gene Heskett wrote:
> > > > 
> > > > auto lo eth0 eth1
> > > 
> > > Agree with Lisi, I've never seen this (though I'm not claiming it's
> > > either wrong or harmful).
> > 
> > It's an ok line. From interfaces(5):
> > 
> >   Lines beginning with the word "auto" are used to identify the physical
> >   interfaces to be brought up when . . . .
> > 	   ^
> > 	   |
> > 	   ^
> > 	   |
> > 	 Plural
> 
> Sorry, that wasn't my point. Here's the context again:

Sorry. Hopefully it will be useful for someone, though. :)

> On Wed 18 May 2016 at 10:56:01 (-0400), Gene Heskett wrote:
> [...]
> > Now,  for those complaining about my lack of posting the complete
> > interfaces file, here it is:
> > --------------------------------------------
> > # This file describes the network interfaces available on your
> > system
> > # and how to activate them. For more information, see interfaces(5).
> >
> > auto lo eth0 eth1
> >
> > # The loopback network interface
> > iface lo inet loopback
> > address 127.0.0.1
> > netmask 255.0.0.0
> 
> Agree with Lisi, I've never seen this (though I'm not claiming it's
> either wrong or harmful).
> 
> To elaborate, interfaces(5) says:
> 
>    The loopback Method
>        This method may be used to define the IPv4 loopback interface.
> 
>        Options
> 
>               (No options)
> 
> So these options:
> 
> > address 127.0.0.1
> > netmask 255.0.0.0
> 
> may or may not cause trouble.

127.0.0.1 is a class A address so has 255.0.0.0 as its netmask. The line
above above is redundant. The installer never uses it. Why a user would
add it is beyond me. I have

  brian@desktop:~$ /sbin/ifconfig lo
  lo        Link encap:Local Loopback  
            inet addr:127.0.0.1  Mask:255.0.0.0
            inet6 addr: ::1/128 Scope:Host
            UP LOOPBACK RUNNING  MTU:65536  Metric:1
            RX packets:695157 errors:0 dropped:0 overruns:0 frame:0
            TX packets:695157 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:0 
            RX bytes:135710702 (129.4 MiB)  TX bytes:135710702 (129.4 MiB)

without that line. As can be seen, the netmask is sorted out automatically.