Re: IP Address networking - best way?

[Alan Chandler <alan@chandlerfamily.org.uk>]

On Friday 12 January 2007 02:00, Andrew Sackville-West wrote:
> On Fri, Jan 12, 2007 at 03:04:08AM +0200, Justin Hartman wrote:
> > On 1/12/07, Michael Bellears
> >
> > <michael.bellears@generalcommunications.com.au> wrote:
> > >Bah....fat fingers! Try auto eth0:0
> >
> > The problem with auto eth0:0 is that last time I did this and I ran
> > a networking restart I completely shut down my server from external
> > access. I had to get the datacenter to remove the auto and then I
> > could get back into my machine.
>
> I believe that when you brought this up before you were told that
> eth0 and eth0.0 are the same thing and that was the problem. you need
> either eth0 and eth0.1 or eth0.0 and eth0.1. If it wasn't you, sorry.
> :)

I don't think that is an issue.  My /etc/network/interfaces file 
follows.  Essentially this machine is my router connecting via eth0 to 
the internet (and using dhcp from my ISP to get me an IP address - and 
prerunning the firewall as it comes up) on the lan side are a set of 
interfaces from a single network card based around eth1.  This all 
works perfectly and eth1 and eth1:0 have separate ip addresses.

I wonder if the original poster is having problems because he needs to 
allow ip forwarding.  

# /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)

# The loopback interface
auto lo
iface lo inet loopback

# The first network card - this entry was created during the Debian 
installation
# (network, broadcast and gateway are optional)
#

auto eth0
auto eth1
auto eth1:0
auto eth1:1
auto eth1:2
auto eth1:9

# This is the network card for connecting from the outside (MAC address 
registered)
iface eth0 inet dhcp
        pre-up /etc/firewall $IFACE
        pre-up echo 1 > /proc/sys/net/ipv4/ip_forward

iface eth1 inet static
        address 192.168.0.20
        netmask 255.255.255.0

iface eth1:0 inet static
        address 192.168.0.30
        netmask 255.255.255.0

iface eth1:1 inet static
        address 192.168.0.31
        netmask 255.255.255.0

iface eth1:2 inet static
        address 192.168.0.32
        netmask 255.255.255.0

iface eth1:9 inet static
        address 192.168.0.39
        netmask 255.255.255.0



-- 
Alan Chandler
http://www.chandlerfamily.org.uk