Multiple Loopback Interfaces

[Dan Williams]

On Thu, 2013-08-29 at 15:46 +0200, Reindl Harald wrote:
> 
> Am 29.08.2013 15:38, schrieb John Chludzinski:
> > I need to used multiple loopback addresses (interfaces) for an server
> > application that communicates with multiple clients running on the same
> > machine.  Since a loopback interface short circuits the network stack
> > (looping back in the IP layer) it is a more efficient means of
> > communication, hence better for my purpose.
> > 
> > How do I define multiple loopback interfaces?
> > 
> > BTW, I'm a newbie to this mailing mailing list.  Hopefully this is an
> > appropriate question?
> 
> if you are running network.service it's trivial
> NetworkManager -> no ida, i do not touch it

NM does nothing with lo, so the same procedure below would certainly
apply if you're running NM.  Touch lo all you want.

Dan

> ___________________________________________
> 
> [root at rh:/etc/sysconfig/network-scripts]$ cat /etc/sysconfig/network-scripts/ifcfg-lo:1
> DEVICE=lo:1
> IPADDR=127.0.0.2
> ONPARENT=yes
> 
> [root at rh:/etc/sysconfig/network-scripts]$ ifup lo:1
> 
> [root at rh:/etc/sysconfig/network-scripts]$ ifconfig lo:1
> lo:1: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
>         inet 127.0.0.2  netmask 255.0.0.0
>         loop  txqueuelen 0  (Lokale Schleife)
> 
> [root at rh:/etc/sysconfig/network-scripts]$ ping 127.0.0.2
> PING 127.0.0.2 (127.0.0.2) 56(84) bytes of data.
> 64 bytes from 127.0.0.2: icmp_seq=1 ttl=50 time=0.056 ms
> ___________________________________________
> 
> that's the "lo" config shipped with Fedora
> 
> [root at rh:/etc/sysconfig/network-scripts]$ cat /etc/sysconfig/network-scripts/ifcfg-lo
> DEVICE=lo
> IPADDR=127.0.0.1
> NETMASK=255.0.0.0
> NETWORK=127.0.0.0
> # If you're having problems with gated making 127.0.0.0/8 a martian,
> # you can change this to something else (255.255.255.255, for example)
> BROADCAST=127.255.255.255
> ONBOOT=yes
> NAME=loopback
>